Welcome to the BoliOptics comprehensive glossary of microscopy industry-specific and technical terminology. Whether you're a researcher, technician, student, or industry professional, this resource is designed to help you better understand the language and concepts commonly encountered in optical and digital microscopy.

Each term listed below is followed by an explanation, offering insight into its definition, context, and relevance within the broader scope of scientific imaging and analysis. This page serves as a reliable reference for anyone working with or studying microscopes—making complex terms more accessible and easier to understand.

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Microscopy Terms

Biological Microscope

Biological microscopes are compound microscopes that are primarily used to observe and study organisms and microorganisms.
Biological microscopes were the earliest type of microscopes to be invented and the most widely used compound microscope today. Humans first used simple microscopes to observe tiny objects with a lens. Later, compound microscope were invented, which then used two lenses, i.e., one eyepiece and one objective lens for secondary imaging, to obtain a larger multiple of the image.
Conventionally, we usually refer to microscopes that include various accessories such as phase contrast, fluorescence, and polarized light etc. as compound microscopes, to distinguish them from stereo microscopes. (Although stereo microscopes also have an eyepiece and an objective lens, they have two light paths, which presents a three-dimensional image).

The most basic biological microscope consists of an eyepiece, an objective lens, a microscope stage, and light source. Both the eyepiece and the objective lens are convex lenses. The objective lens first enlarges the object into a real image. The eyepiece then magnifies the real image again into a virtual image, and finally becomes an inverted magnified virtual image on the retina of the human eye.
Biological microscopes are usually used to observe transparent or translucent objects, such as animal and plant cells, tissues, bacteria and microorganisms, as well as various kinds of tiny particles by means of sectioning. They are widely used in teaching, medicine, animal or plant research and industrial fields. Modern optical microscopes have made great progress in the wavelengths of various kinds of light; illumination forms, resolution, microscope functions, structure and comfort of image acquisition and analysis, and basically meet various research needs.
According to the user's needs and the complexity of the product, general biological microscopes are divided into student-level, experimental-grade, and research-level biological microscopes.

Basic Structure of Biological Microscope
A standard biological microscope usually has at least the following basic structures:
1. Objective lens - the closest imaging lens to the observed specimen. Objective lens determines the most important properties of the microscope imaging; such as wavelength and resolution of the object light. A microscope can have several objective lenses with different magnifications.
2. Eyepiece - the lens mounted on the upper end of the microscope tube; close to the observer's eyes. Generally, microscopes can have several eyepieces with different magnifications.
3. Light source - the light source of the biological microscope is under the microscope stage. According to different needs, a light source may include an illuminating light source (bulb), an aperture diaphragm, a condenser etc. The condenser is used to condense the illumination light and also increase the illumination brightness of the specimen. Aperture diaphragm, also called iris, is used to adjust the luminous flux of light. Under the aperture diaphragm, there is usually a circular filter holder, and the optical filters are placed according to needs. A simple microscope would not have an illuminating light source, it is illuminated by natural light, and a reflector is used to illuminate the object to be observed.
4. Microscope base - located at the bottom of the microscope; to support the lens body. Usually, the light source and the electrical appliances are installed inside the base and above the base.
5. Microscope body - used to connect and stand the various components of the entire microscope, and it is also the part the user holds when moving the microscope.
6. Microscope tube - an optical path channel connecting the eyepiece and the nosepiece of the microscope.
7. Nosepiece - the turntable under the microscope tube. The nosepiece usually has 3 to 4 circular holes for mounting objective lenses of different magnification; which can be rotated onto the optical axis of the microscope for use.
8. Microscope stage - where the specimen is placed for observation. There are usually two metal tablets on the mobile station, which are used to fix the specimen of the slide. There is also usually a pusher installed for moving the specimen. There are also microscope stages that can be moved directly in the XY direction.
9. Focus knob - used to adjust the distance between the objective lens and the microscope stage (sample) to bring the objective lens into focus to get a clear picture or image. The focus knob is usually mounted with the microscope stage to achieve the purpose of moving up and down focusing through the coarse focus knob and the fine focus knob.

Biological Microscope Quick Operation Steps
Step 1. Install and Prepare:
The configuration of the biological microscope is mostly standard. Carefully check the parts on the packing list and the information on the BoliOptics website to assemble and install the microscope.
The microscope should be placed on a solid and stable work surface with the tabletop kept steady, clean, and close to a power source. It is best to place the microscope out of direct sunlight. Generally speaking, the darker the environment, the better the image is observed by the microscope. Stray light greatly influences the imaging when the microscope is used for observation, as it can damage the specimen and can also accelerate the aging of the microscope surface and components.

Step 2. Turn on the light source:
Connect the power source, turn on the power switch, and adjust the light source to a position where the brightness is moderate.

Step 3. Place the specimen (also known as the type or sample):
Adjust the coarse focus knob first, and raise the objective lens to a higher position for easy placement of the specimen. Place the slide specimen of the observed object on the microscope stage. Note that the side of the cover slip is placed face up. Then use spring pressure to clamp on both ends of the slide to prevent the specimen from moving, and then adjust the knob through the XY direction of the microscope stage to move the general position of the part of the specimen to be observed to the center of the condenser.

Step 4. Adjust the parfocal of the high and low objective lens:
First observe with low power objectives. Adjust the low power lens (such as 4X, 10X) from the objective lens or nosepiece to the optical axis. Then, adjust the focus knob to find the outline of the image. Because the low power objectives have a large field of view, it is easier to find the image and determine the part to be observed. At the same time, adjust the XY microscope stage hand button to find the position of the specimen to be observed. It should be noted that the image of the biological microscope in the field of view is usually an inverted image, that is, the specimen should be moved in the opposite direction when moving the specimen.
Then, turn the nosepiece and gradually use the high power objective (such as 40X) to move to the observation position, and finally to the maximum magnification (such as 100X). During the process, continually adjust the fine adjustment knob to find the clearest image.
With regard to the observation and use of the oil lens, it is generally carried out after the above steps, and finally make further accurate observation.

When changing from low power objectives to high power objectives, the object image can generally be seen, but it may not be very clear. When rotating to the maximum power objectives (such as 100X), only the fine focus knob should be used rather than the coarse focus knob, so as to avoid damage to the lens or the slide specimen. When the image of the maximum power objective is clear using a microscope with normal function, ensure that the low power objectives and the high power objectives are parfocal, and the focus knob is no longer adjusted. During operation, it is possible that the power of some of the objectives in the middle may not be parfocal. If so, you only need to adjust the fine focus knob slightly.
Using a binocular microscope - If the observer's binocular vision is different, adjust it by the eyetube diopter of the eyepieces. Do not adjust the focus knob.

Step 5. Adjust the Light Source:
Adjust the light intensity of the light source. Adjust the size of the diaphragm, the height of the condenser, the angle of the reflector. These adjustments need to be coordinated and adjusted with the power of objective in order to get a clear image.
Under normal circumstances, the light of the stained specimen should be strong, and the light of the colorless or unstained specimen should be dim. When adjusting between high and low power objectives, the light for low power objectives for observation should be dim, and the light for high power objectives for observation should be strong.

Step 6. Replace the specimen:
After observing the specimen - if you need to switch to another slide, you should first change the objectives back to low power, remove the slide before replacing it with a new one, and then adjust the focus again for observation. Do not change the specimen under the high power objectives as the working distance is very small, so as to prevent damage to the objective lens.

Step 7. Arranging the microscope after use:
After observing with the microscope, the objective lenses should be moved away from the light-passing hole. Turn the nosepiece so that the V-shape between the lenses is slanted to both sides.
Remove the sample.
Check the light source of the microscope - adjust the aperture diaphragm to the maximum, adjust the brightness knob to the darkest, and then turn off the power button to prevent the instantaneous high current from burning out the light source when the power is turned on next time.
Lower the microscope stage and check if any parts are damaged, if the objective lens is stained with water or oil, or if the objective body has stains or hand prints. Wipe the microscope clean, and check that the accessories are complete, the sample specimens are complete, and anything else is complete.
After the final inspection is completed, cover the microscope with a dust cover or place the microscope into a box.

Biological microscopes are the basic structure of other forms of compound microscopes that are added with various kinds of accessories or attachments. Many principles and key points are fundamentally reflected in biological microscopes.

Stereo Microscope

Stereo microscopes are also known as the anatomical microscopes, or dissecting microscopes. Many people would refer to stereo microscope as Stereo, and the Continuous Zoom Microscope as Zoom.
Stereo microscopes are a kind of binocular microscope that observes an object with both eyes from different angles, thereby causing a stereoscopic effect.
The stereo microscope adopts two independent optical paths, and the left and right beams in the binocular tube have a certain angle, generally 12°~15°. The objects are observed from different angles of the two optical paths, causing a three-dimensional effect on the eyes, and therefore a stereo microscope is a true 3D microscope.

Compared with other compound microscopes, stereo microscopes belong to the low power optical microscope. The field of view of stereo microscopes has a large diameter, its magnification is generally below 200X for optical magnification. When the magnification is greater than 40X, the stereoscopic effect of the image will be relatively poor.
Therefore, the advantage of the stereo microscope is not that its magnification is large, but that its working distance is long and the depth of field is large, which is particularly suitable for observing objects with a high degree of three-dimensional features.
For compound microscope with a single optical path, what we see is only a flat image. Although most compound microscopes have two eyepieces, what we actually see is one and the same image, and this is just to facilitate the observation habits of our two eyes. The stereo microscope has two optical paths (two objective lenses or one common objective lens), and only the three-dimensional sense produced under observation of the two optical paths can make people judge the three-dimensional spatial position of the observed object, which can generate a sense of distance under the microscope. Therefore, only stereo microscope can be used for operation under the microscope which is very suitable for surgery, dissection, industrial welding, assembly, precision instrument repair and so on.

The stereo microscope can be equipped with a wide range of accessories. It can be combined with various digital cameras and photographic interfaces, microscope cameras, eyepiece cameras and image analysis software to form a digital imaging system. It can be connected to a computer for analysis and processing, and its lighting system also has different options for illumination, such as reflected light, transmitted light, etc.
Stereoscopic microscopes are widely used in various fields, such as biology, medicine, agriculture, forestry, marine life, and other various departments. They are especially used in industry, for macroscopic surface observation, analysis, and microscopic operations.

Stereoscopic microscopes were invented by American instrument engineer Horatio S. Greenough in the 1890s, manufactured by Carl Zeiss Company of Germany, and are widely used in scientific research, archaeological exploration, industrial quality control, biopharmaceuticals, and more.

Stereo Microscope Quick Operation Steps
Step 1
In the working position, place the microscope on the workbench after installation.
Connect the power source, and turn on the light source.
Place an observation sample (also known as specimen) such as a coin etc. under the microscope or on the base.
Adjust the focus knob of the stand by visually measuring the height, or based on the working distance parameters of the objective lens used.

Step 2
Adjust the zoom knob of the microscope to the lowest magnification. Find the approximate image by adjusting the focus knob. Find a certain feature point of the sample in approximately the center position.
Align the feature point of the specimen and gradually adjust to a large magnification.
Adjust the lift set of the microscope to find the focal plane of the highest magnification. During the adjustment process, use a sample with obvious feature points (such as a coin) to compare the sharpness of the image.
Turn the zoom knob again to the lowest magnification. It is possible that the image may be out of focus. At this time, do not adjust the focusing knob. Simply adjust the diopters on the two eyepieces to accommodate differences in eye observations (diopter varies from person to person).
Adjust the viewing distance of the eyepiece to achieve a comfortable position.
At this point, the microscope is already parfocal, i.e., when the microscope is changed from high power to low power, the entire image is in the focal plane. To observe the same sample, it is not necessary to adjust other parts of the microscope. Only the zoom knob is needed to zoom in on the specimen for observation.

Step 3
Adjust the light source, including the brightness and angle of incidence to get the best image or see additional details.

Step 4
Adjust any other necessary equipment such as the photographic eyepieces, cameras, etc., to show the image on the display or to find the sharpest image.

When using binocular observation and the left and right images or sharpness is not the same, first adjust the diopter adjustment on the eyepiece. This adjusts the parallax of the two eyes, so that the image of the two eyes are consistent. It is normal to feel viewing fatigue when using a microscope for a long time. Take a break before working again to adapt your eyes to using the microscope. If the microscope is used for too long, or if there is a problem inside the microscope due to large temperature difference, vibration, etc., please contact your dealer or our service staff on the BoliOptics website.

Metallurgical Microscope

A metallurgical microscope is a microscope that uses incident illumination (also known as reflection light) to observe the metallurgical structure of the surface of a metal specimen and perform microscopic analysis. Metallurgical microscopic analysis is widely involved in the material microstructure, internal components, state imaging, and qualitative and quantitative analysis, including the quantitative and spatial distribution of the phase and tissue structure, composition, crystallization and sub-crystallization, non-metallic inclusions, and tissue defects of the materials etc.

Metallurgical microscope is one of the important components of industrial microscope. In addition to observing metal surface, metallurgical microscope plays an important role in metal heat treatment and cold processing. It is no longer limited to metal research, as it is also widely applied in other opaque or translucent objects, including fibers, soils, minerals, crystals, ceramics, surface treatments, integrated circuits, LCD screens, and other industries. Modern Metallurgical microscope not only have good optical systems, but also combine optical microscope, photoelectric conversion technology, and computer image processing technology to easily observe metallurgical images and analyze and rate metallurgical maps.

The quality of the image is the primary indicator of metallurgical microscope. Metallurgical microscope needs the basic conditions of optical imaging such as high brightness, high contrast, high resolution and good color reproduction. At the same time, due to the environment applied, the microscope needs to be solid and durable.
Metallurgical microscope generally uses coaxial reflection light method. The illuminating light passes through a coaxial reflection illuminator, after rotating a 90 degree angle, it is irradiated vertically (or nearly vertically) to the surface of the object to be observed, and then reflected back into the eyepiece through the objective lens.

Notes on the Use of Metallurgical Microscope:
When the observed metal surface is too rough, due to the diffusing effect of the incident light, the microscope cannot observe its internal structure, grinding and polishing of the surface of the metal sample must be carried out. However, during the process, no tissue structural change should occur on the surface; when some metal structures have a particularly strong surface reflection, it is necessary to use a certain reagent for corrosion treatment, dissolve some components, and thus see the morphology of the tissue.
Metallurgical microscope are complex in function and diverse in components, and often large-scale metallurgical microscope are modular and require self-installation and commissioning. Be sure to read the operating manual first and carefully check the completeness of the components.
Prior to installation and use, installation and adjustment of location of components are required. In particular, the positional adjustment of the light source in the coaxial reflection illuminator has a very big influence on the brightness and uniformity of the imaging illumination.

For more information on the use of metallurgical microscopes, please refer to the Biological Microscope Biomicroscope on the BoliOptics website.

Fluorescence Microscope

A fluorescence microscope is a microscope that uses ultraviolet light as a light source to illuminate an object to be observed to make it emit fluorescence, and able to observe information on the position, shape, and structure of the fluorescent portion of the object.
Some substances in nature can fluoresce themselves when exposed to ultraviolet light. Some substances cannot fluoresce themselves, but they can also fluoresce after being dyed with fluorescent materials. Fluorescence microscope is an important tool for studying cytology. It is widely used in scientific research and teaching fields such as medicine, polymer structure, and luminescent materials research, and so on.

The most important feature of the fluorescence microscope is that it has an illumination source that can emit ultraviolet light, forming a lighting system with the configured fluorescence condenser and filters that are designed for excitation and acceptance of fluorescence.
Fluorescent light sources generally use mercury or metal halide lamps, as well as high-power LEDs or laser sources. The ultraviolet light emitted by the light source has a shorter wavelength and thus has a higher resolution. Generally, the high-pressure mercury lamp has a continuous spectrum and a large irradiation intensity, making it a relatively ideal fluorescent microscope source; the xenon lamp has stable intensity in the visible light spectrum range and higher intensity in the infrared band than the mercury lamp, but has certain defects in the ultraviolet band. High-power LED light source cannot provide continuous band spectrum, but has advantages in the range of specific wavelengths, there is no need to preheat, start up and use, has long service life and low labor maintenance cost. So when choosing a light source, you need to understand the characteristics of the light source to match the specific application. Halogen lamps have a narrower range of excitation light wavelengths and can only be concentrated in certain specific wavelengths, such as blue light, so applications are less.

Fluorescence microscope can use transmitted light and reflection light for illumination. It can also be installed with a dark field device to become a dark field fluorescence microscope. A phase contrast accessory can be added to form a phase contrast fluorescent microscope, or an interference device can be added to become a fluorescent interference microscope.
Reflection light is also commonly called incidence light fluorescence microscope, also known as the EPI-Fluorescence Microscope. The illumination source and the excitation light are passed through the same objective lens. The excitation light path does not pass through the slide as it is directly irradiated onto the specimen, with small excitation light loss and high fluorescence efficiency.
The illumination path of the transmitted light fluorescence microscope needs to pass through the slide. In order to reduce the loss of the excitation light, the transmissive fluorescence microscope should use quartz glass slides and coverslips. Because, as consumables, quartz slides are expensive, people prefer to use an EPI-fluorescence microscope.
The inverted fluorescence microscope is composed of fluorescent accessories and an inverted microscope. The objective lens and the condenser have a long working distance, and can directly observe and study the object in the culture dish, characterized by microscopic observation in a culture flask or petri dish, mainly used for fluorescence of living tissues such as cells, and are suitable for microscopic observation of tissue culture, in vitro cell culture, plankton, food inspection, etc. in the fields of biology and medicine.

Fluorescence microscope systems require the use of two sets of filters for both excitation and emission (Emission) processes.
1. Excitation: After the light source emits light, it first enters the incident light filter, filters out the visible light, and only retains the wavelength portion for exciting the sample, therefore the incident light filter is called an exciter filter.
2. Then, the excitation light is directed vertically to the objective lens through the dichroic lens or a reflector, and then to the specimen through the objective lens, so that the specimen is excited to generate fluorescence and, at this point, the objective lens directly functions as a condenser.
3. The fluorescence, after excitation, is reflected back through the objective lens to the dichroic lens and the barrier filter to block other light except the wavelength of the emitted light from the sample (i.e., the fluorescent portion), so that the observer observes through the eyepiece or the camera to form image. The barrier filter can also filter out the ultraviolet rays between the eyepiece and the objective lens to protect the observer's eyes.

The reflective layer on the reflector of fluorescent microscopes is generally aluminized. Aluminum absorbs less ultraviolet and visible light in the blue-violet region and reflects more than 90%, while silver reflects only 70%.

The condenser of the fluorescence microscope is made of quartz glass or glass that can transmit ultraviolet light. It can use bright field condensers and dark field condenser, and there is also the phase contrast fluorescent condensers. The bright field condenser has strong condensing power, convenient to use, and is suitable for low and medium multiple power observation. The dark field condenser can produce a dark background because the excitation light does not directly enter the objective lens, thereby enhancing the brightness and contrast of the fluorescent image, capable of observing the fluorescent fine particles that cannot be distinguished by the bright field. The phase contrast fluorescent condenser needs to be used together with the phase contrast accessories and the phase contrast objective lens to observe the phase contrast and the fluorescence effect at the same time. It can see both the fluorescence image and the phase difference image, which helps the accurate positioning of the fluorescent structure.

Ordinary fluorescence microscopes can adopt various kinds of conventional objective lenses. As the more the number of lenses of the objective lens, the greater the loss of fluorescence, and in particular, the apochromatic objective lens contains quartz and other components, which can spontaneously fluoresce to form interference, therefore, the general use of flat field achromatic objective lens can already achieve very good results. The fluorescence brightness in the field of view of the microscope is proportional to the square of the numerical aperture of the objective lens, and inversely proportional to the magnification. For specimens with insufficient fluorescence, in order to improve the brightness of the fluorescence image, an objective lens with a large numerical aperture should be used, especially when using high power microscope for observation, it is often necessary to use a dedicated high-magnification fluorescent objective to provide excellent chromatic aberration correction and image quality.

Fluorescence Microscope Camera and Image
A fluorescence microscope camera can be connected to a fluorescence microscope to form a fluorescence microscope imaging system. The fluorescence image seen by the fluorescence microscope has both the morphological features, the fluorescent color and brightness and other features, and the two need to be combined for comprehensive judgment.
The brightness of the fluorescence is relatively weak, and it usually requires the camera to have high sensitivity to low light and signal capture ability in order to obtain a good fluorescence image. The camera can adjust the focus with a brighter fluorescent area. Adjust and set the exposure compensation according to the distribution ratio of the fluorescent image in the photometric area and the brightness of the image. Generally, it is necessary to increase the exposure compensation appropriately to obtain a bright and vivid fluorescent image on a dark background. The camera needs to adopt the appropriate fluorescence shooting mode, do the appropriate background subtraction processing, and set the appropriate parameters, such as Binning, Gain, Gamma, etc., so that the exposure time and gain can be maximized by software control.
Fluorescence microscope can also use a fluorescent cold-cooling camera to reduce noise and improve the signal-to-noise ratio of the image. Especially in low light conditions, using dark field illumination, or under chemiluminescence conditions, long time exposure is required. Using a cooling camera can reduce the dark current noise and obtain a clearer image.
In the weaker fluorescence field of view, in order to obtain a better contrast image, appropriate adjustments should be made to reduce the fluorescence aperture diaphragm so as to obtain images with large depth of field, or use a neutral density filter (ND for short).
When shooting with a high power or magnification objective, any vibration should be avoided, and it is best that an anti-vibration table should be configured.

The slides and coverslips used in fluorescence microscope must have a smooth surface, uniform thickness, and no autofluorescence. The thickness of the slide should be between 0.8~1.2mm. The thickness of the standard coverslip is about 0.17mm. If the slide is too thick, it will cause short-wave excitation light and fluorescence loss. If necessary, quartz glass slides can be used to increase the fluorescence transmittance.
The tissue section or other specimen of the fluorescent specimen is usually about ≤10μm, should not be too thick, otherwise it will affect the excitation light penetrating the specimen, and excessive non-essential cell overlap or impurity masking will affect the observation effect of the objective lens on the upper part of the specimen.
The sealant of the specimen must be colorless and transparent, without autofluorescence. The brightness of the fluorescence is brighter at pH 8.5~9.5, and it is not easy to fade quickly. Usually, glycerin can be used. When using dark-field fluorescence microscope or oil lens for observation, lens oil must be used, and it is best to use special non-fluorescent oil. Especially in the U and V-band excitation, the conventional cedar oil will have cyan fluorescence. Glycerin, liquid paraffin, etc. may also be used.

Fluorescence Microscope Operation Precautions
As the fluorescence is relatively dark, so the fluorescence microscope is best placed in a dark room, which also allows the human eye to adapt to the darkness for better observation effect. When lighting required, local lighting can be used. In addition, because some mercury lamps produce a great deal of heat, and some xenon lamps can generate a lot of ozone, and therefore good ventilation is required.

Before use, open the packing list first, check the integrity and status of the parts and accessories, and operate according to the instructions.
Before performing fluorescence observation, first check the condition of the lighting equipment of the fluorescent device, turn on the halogen light for illumination first, place a sample film, and do the lens focusing and centering the filament in advance. Then, check whether the fluorescence excitation filter and the emission filter are installed in the nosepiece, and whether the objective lens configuration is proper. If there is a phase contrast observation of transmitted light in the system, check the convergence axis of the condenser lens in advance, and whether the phase contrast ring plate and objective lens are matched correspondingly.
Inspect the slides, coverslips, and other sample vessels, whether the thickness of the sample is within the range of the calibrated working distance of the objective lens, and whether there are liquid, smudges, dust and other interference.
Because the illumination source contains ultraviolet light, avoid looking directly at the ultraviolet light source when the light source is adjusted. The fluorescence microscope should be equipped with a brown UV protection visor to prevent UV damage to the retina of the eyes.

After the above inspection, place the specimen to be tested and turn on the high-pressure lamp source. When the high-pressure mercury lamp is fully lit, stop the excitation and then observe.
Generally, after the high-pressure mercury lamp is turned on, the excitation light intensity tends to be stable in about 5-10 minutes, and reaches the brightest point in 15 minutes. The working time when the mercury lamp is turned on is preferably 1 hour each time. Exceeding 90 minutes, the excitation light intensity will gradually decrease and the fluorescence will be weakened. After 15 minutes of excitation of the specimen, the fluorescence will also be significantly attenuated.
After the high-pressure mercury lamp is turned off, it cannot be re-opened immediately. I can be started again only after it is completely cooled. Otherwise, the mercury lamp will be unstable and affect the service life.
After the mercury lamp is turned off, it takes at least 10 minutes to start again, so that the mercury vapor is cooled to the original state, otherwise the service life of the bulb will be affected.
The power supply should be equipped with a voltage regulator, which will reduce the service life if the voltage is unstable.
The excitation device of the fluorescence microscope and the high-pressure mercury lamp have a limited life span, and the specimens should be collectively inspected in batches so as to reduce the number and time of mercury lamp activation.

First, observe with a low power objective lens, ensure that the specimen is located in the center of the entire illumination spot, and then gradually changed to high power observation. Under the premise of not affecting the resolution, the adjustment ring of the field diaphragm and of the numerical aperture diaphragm of the objective lens can be minimized as much as possible to reduce the excitation area, avoid the influence of stray light, and improve the depth of field.
When observing the sample, in order to prevent the fluorescence of the sample from quenching due to excessive excitation of light illumination during the process of focusing and searching for the image, it is best to adjust the excitation light to a moderate intensity by first reducing the aperture diaphragm or using the ND filter. After finding the key feature points, adjust the fluorescence to the optimal brightness, and finally observe and take pictures.

Long-time excitation light illumination of the specimen will cause the fluorescence to attenuate and disappear. Therefore, the specimen should be observed immediately after dying. If stored for too long, the fluorescence will gradually weaken until quenching. When not observed for a while, the excitation light path should be blocked by a visor. The dyed specimens can be wrapped in black paper, placed in a polyethylene plastic bag, and stored at a low temperature of about 4 °C, which can delay the quenching time of the fluorescence and prevent the sealing agent from evaporating.
Before and after use, the grease and dust contaminating the lenses in front of the objective lens should be inspected and removed. Gently brush it with a soft brush. In the place where fingerprints and oil stains are present, use a soft, clean absorbent cotton, lens rubbing paper dipped in anhydrous ethanol (or methanol) to gently wipe clean, and wipe the oil stain on the surface of the objective lens with gasoline

For more information on the use of fluorescence microscope, please refer to the Biological Microscope on the BoliOptics website.

Polarizing Microscope

Polarizing microscope, also known as polarized microscope, is widely used in geology and mining, and is therefore often referred to as the polarized metallographic microscope or geology microscope.
The polarized light is used to observe the phenomenon of "optical anisotropy" (refers to the uneven spatial distribution of optical properties) and measure the relevant parameters, the ordinary light of the microscope is changed to polarized light, to this end, the polarized light attachment device is added.

In some general-purpose microscopes, two polarizing plates are added: a polarizer is added to the incident light path, and an analyzer is added to the observing optical path to obtain polarized light illumination, which becomes a polarizing microscope. Polarizing microscope is often used for research in the field of opaque objects such as minerals, general biology, and medicine.
Dedicated transmissive or reflective polarizing microscopes, their series of components, including eyepieces, objectives, stages, microscope tubes with Bertrand Lens, condensers and compensators, are all designed to meet specific needs. The polarizing microscope can perform single-polarization observation, orthogonal polarization observation, conoscopic observation, and identification of birefringent materials by the polarization characteristics of light for crystallography research, stress science and research of other disciplines. At the same time, it is also widely used in the fields of minerals, petroleum, semiconductor industry, chemistry, etc., as well as medicine, biology and botany.

Polarizing microscopes can be divided into reflection, transmitted, and reflective and transmitted microscopes. The main special structures and accessories of polarizing microscopes include polarizers, analyzers, and some polarizing accessories.

Polarizer and analyzer are the most important polarizing devices for polarized microscopes. They were originally composed of Nicola Prism. Nowadays, artificial polarizers, PL for short, are mostly used. Light that vibrates in a certain direction can pass through selectively, and becomes linearly polarized light that vibrates in a straight line. What is mounted between the light source and the observed sample is called polarization lens (polarizer), also known as lower polarization lens. What is mounted between the objective lens and the eyepiece is called analyzer, also known as lower analyzer, can change direction by rotation and is marked with a rotation angle scale.
The light source of the polarizing microscope usually uses full-color light. Generally, a common white light source can be used. If necessary, monochromatic light can be used, or a color filter can be added, so that the speed, refractive index, and interference phenomenon of the light differ depending on the wavelength. Polarizers usually filter out most of the light, so polarized microscopes must use a relatively strong light source.
For objective lenses of polarized light microscopes, a "stress free" achromatic objective lens should be used, usually marked with a "P" mark, especially higher power apochromatic and semi-apochromatic objective lens, as they themselves contain fluorite components, which can cause polarization to form interference.
The nosepiece is usually mounted with an adjusting device to compensate the eccentric position of each objective lens, so that the field center of the objective lens is aligned with the center of the microscope stage, and for some microscopes, their rotating table is mounted with centering knob.
The eyepiece of polarizing microscope requires the use of an eyepiece with a cross-hair reticle. The built-in cross-line scale is used in combination with a polarizing microscope-specific "polarizing tube" to adjust the center position of the centering nosepiece, so that the target crystal sample is rotated at the intersection of the cross for observation.
The Bertrand Lens, also known as the B Lens, is located between the eyepiece and the analyzer, and is combined with the eyepiece to form a set of telescopes that can be pulled out from the optical path and centered for focus. When used in conic optical detection system, conic optical lens can be added on the basis of orthogonal polarization for interferogram observation
The stage of the polarizing microscope is a kind of circular stage that can rotate 360°. It can be scaled around, and some have a main scale and a sub-scale. It can measure the rotation degree and the division number of the specimen details, and some also have a rotational reading that measures the solid angle. Some stages are also provided with a 45° positioning device from any angle, so that the extinction position and the diagonal position can be judged from the hand feeling.
For condenser of polarized light microscopes, it is required that the lens has no stress. In order to achieve parallel polarized light, a swing out condenser that can push out the upper lens should be used.

Use of Polarized Microscope

The principle of polarized microscope is mainly to use the characteristics of the optical "anisotropy". When a beam of light is incident on an anisotropic crystal, it is split into two beams of light propagating in different directions. This phenomenon is called birefringence. Birefringence is a basic property of crystals, such as calcite in uniaxial crystals, quartz lamps, mica in biaxial crystals, gypsum crystals, and various kinds of biocrystals. When the light passes through the birefringent body, the vibration directions of the two polarized lights are different depending on the type of the object. A polarizing microscope can detect the single refraction (isotropic) or birefringence (anisotropic) of a substance.
When the light emitted by the light source passes through the two polarizers, if the directions of the polarizer and the analyzer are parallel to each other, the linearly polarized light formed by the polarizer can completely pass, and the field of view is the brightest at this time. If the two are perpendicular to each other, the light cannot pass at all, and the field of view is completely dark at this time. This vertical position of the polarizing plate and the analyzing plate is called "orthogonal analyzer position"; if the two are tilted, only a part of the light is passed, and the field of view has medium brightness.

Single polarized specimens does not use the above-mentioned analyzer, the condenser and the Bertrand Lens , but only the polarization observation method wherein a polarizer is used to observe in one direction, and it is often used to observe the topographical features of minerals, such as crystallinity, cleavage, color, matte and bulge

Cross polarized specimens, also known as "positive image inspection", is that under the cross detection position, there is no light transmitted, and the field of view is dark. If the object to be inspected is optically isotropic (single refractor), the field of view of the rotating stage will still be dark; if the object to be inspected has birefringence characteristics or contains a material having birefringence characteristics, the field of view of the position with birefringence characteristics will become brighter, this is because the linearly polarized light emitted from the polarizer generates two types of linearly polarized light with different vibration directions after entering the birefringent body. When these two kinds of light pass through the analyzer, as the other beam is not orthogonal to the polarization direction of the analyzer, the image can be seen by the human eye through the analyzer.
When rotating the stage while the birefringent is at the quadrature analyzer position, the image of the birefringent has four times of changes in brightness in the 360° rotation, and darkens every 90°. The darkened positions are where the two vibration directions of the birefringent coincide with the vibration directions of the two polarizers, which are called "extinction positions". When rotated 45° from the extinction position, the object to be observed becomes the brightest, which becomes the “diagonal position”. This is because when the polarized light reaches the object while deviating from 45°, part of the light decomposed can pass through the analyzer, so it is bright.

Conoscopic observation is commonly used for the discrimination of uniaxial crystals, biaxial crystals, confirmation of the cutting surface orientation and axial direction, as well as discrimination of normal crystals and negative crystals, etc.
Conoscopic observation is to illuminate the sample with a large numerical aperture of light in the observation while the polarized microscope is at its quadrature analyzer position, and use the objective lens to focus with also a large numerical aperture in order to see the information of the light passing through the sample in all directions through the back focal plane of the objective lens. This method of not observing the sample itself directly, but by observing the back focus plane of the objective lens is called conoscopic microscopic examination.

Interference color observation is to observe the birefringent body with mixed light of various kinds of different wavelengths as the light source in the case of quadrature analyzer position of the polarized microscope. When rotating the stage, not only the brightest diagonal position in the field of view appears, but also the color, these colors can help us detect more chemical components of the specimen. The reason for the appearance of color is mainly caused by the interference color (it is also possible that the object itself being inspected is not colorless and transparent). The distribution characteristics of the interference color are determined by the type of the birefringer and its thickness, which is due to the dependence of the corresponding delay on the wavelength of the light of different colors. If the delay of a certain area of the object to be inspected is different from the delay of another area, the color of the light passing through the analyzer will be different.

Polarized Microscope Adjustment Method

1. Polarized microscope rotating platform and the objective optical axis adjustment center position
Place a slice on the rotary table and find a small feature point in the slice that coincides with the center of the crosshair of the eyepiece.
Turn the work table. If the center of the optical axis of the objective lens is inconsistent with the center of the table, then the position of the feature point will rotate away from the center of the crosshair around a circle, and the center of the circle is the center of the workbench.
Adjust the nosepiece, or the two adjustment screws on the platform, so that the objective optical axis coincides with the center of the rotary table.

2. Adjust the Position of the Polarizer
First, the polarizer should be calibrated. The polarized microscope sometimes uses only one polarizer to observe, and it must be confirmed that the vibration direction of the polarizer is consistent with the horizontal and vertical directions of the eyepiece crosshair.
Adjust the vibration direction of the polarizer and the crosshair of the eyepiece reticle: find a piece of cleavage and clear black mica sheet, exit the above-mentioned analyzer, and use only the polarizer below to observe, parallel the cleavage seam of the black mica with the horizontal wire of the crosshair of the eyepiece reticle. At this time, the black mica is light yellow, rotate the polarizer, when the color of the black mica reaches the darkest, the cleavage direction is consistent with the vibration of the polarizer, by this time, its scribe line should be aligned to 0° or 180°.

3. The polarizer and the analyzer should be in an orthogonal position, which is consistent with the horizontal and vertical directions of the eyepiece crosshair.
After the direction of the lower polarizer is calibrated, remove the black mica sheet, push it into the upper analyzer, and observe whether the field of view is in the extinction state. If it is completely dark, it indicates that the vibration directions of the analyzer are orthogonal to each other, otherwise it must be calibrated, that is, turn the upper analyzer to the darkest point in the field of view. When turning, the stop screw of the upper polarizer must be loosened first, and then tighten it after calibrating.

Polarized light microscopes must be kept clean, as most of the material around us is birefringent, such as dust in the air and the mineral dust in the soil, the textile fibers in our clothing, etc., which can interfere with the polarization effect.

For more precautions on the use of polarized light microscopes, please refer to the Biological Microscope on the BoliOptics website.

Phase Contrast Microscope

Phase contrast microscope is a kind of microscope that observes the object using a condenser with an annular diaphragm and a phase difference objective with a phase plate by increasing the contrast of the image by changing the optical path that the diffracted light passes.
The principle of phase contrast microscope is that, under the illumination of the same or similar intensity of light, tiny or microscopic objects (such as living cells and unstained biological specimens) cannot distinguish their difference characteristics, therefore through the small height difference (about 100-1500 angstroms) of their surface, by using the diffraction and interference characteristics of light, increase the contrast of microscope imaging by adding phase contrast ring plates and other accessory devices.
After being focused by the condenser, the illumination light is projected on an annular diaphragm, becoming a tubular beam. By using the height difference of the surface of the object to be observed, the direct light and the diffracted light are separated, and after it is overlapped with the phase plate through the auxiliary lens, about 1/2 of the wavelength is removed from the phase, which makes them impossible to interact, thereby causing changes in intensity, improving the contrast of the specimen observation, and making the various structures clearer.

The difference between phase contrast microscope and ordinary biological or metallurgical microscope is that the variable diaphragm is replaced by annular diaphragm, and the ordinary objective lens is replaced by the objective lens with the phase plate, providing a phase telescope for coupling axis as the main accessory of the phase contrast microscope.
The illumination of a phase contrast microscope requires, first of all, a stronger source of light because the annular diaphragm and the phase plate block and absorb most of the light, and the light entering the imaging diaphragm is relatively weak. Secondly, it is necessary to use Kohler illumination to evenly focus the light on the aperture diaphragm, and ensure the temperature environment of the observed living cells, etc., and further eliminate the heat radiation by adding a heat insulating filter.
In addition, when observing biological specimens, it is best to use a color filter (usually a green color filter). Use a monochromatic light source to ensure adjustment of the refractive index difference of the biological specimen. The image effect produced by the phase contrast microscope is that the bright and dark structural features of the samples can be displayed on a gray background.

Phase contrast microscopes can be divided into transmissive phase contrast microscopes (such as phase contrast biological microscopes) and reflective phase contrast microscopes (such as phase contrast metallurgical microscopes).
By increasing the contrast of the microscope, transmitted light phase contrast microscope can observe living cells and biological samples without staining. It can also be used to observe stained samples with small contrast and small organ tissues. Transmitted light phase contrast microscope is widely used in the fields of biology and pathology such as cells and bacteria.
Reflected light phase contrast microscope can observe the microstructure of microscopic height difference which is not easy to be distinguished by ordinary metallurgical microscope, such as metallurgic, crystal, oil film, chemicals, dust particles, and materials science and other aspects.

Precautions in the Use of Phase Contrast Microscope
1. The thickness of the specimen should be less than 5μm. When the specimen is relatively thick, the upper layer is observed to be clear, but the deep layer will be blurred, and cause phase displacement interference and light scattering interference.
2. For the specimen, cover slip should be used, otherwise the bright ring of the annular diaphragm and the dark ring of the phase plate will be difficult to overlap due to the change of the optical path of the objective lens. At the same time, there is also relatively higher requirements for the quality of slides and coverslips. When surface scratches or irregularities occur, it will produce bright ring skew and phase interference. When the slide is too thick or too thin, it will also affect the size of the ring diaphragm of the annular diaphragm.

For more precautions for use of phase contrast microscope, please refer to the Biological Microscope on the BoliOptics website.

Measurement Microscope

Measurement under the microscope is a kind of non-contact measurement, that is, the measurement tool uses the points, lines, circles, angles, areas, three-dimensional of the image and the complex geometric images of the measured object to measure and calculate without contacting the specimen. For measurements, different optical systems and different measurement methods can be used, from the simplest measurement with scales to tools such as optical measurement platforms, as well as relevant measurement software etc. Measurement microscope is the general term for microscopes with this type of function.
Non-contact measurement can measure the data of some small and irregular objects that are not accessible by conventional measuring tools. Especially after amplification of the microscope, its measurement accuracy can be very high, and the error caused by the optical system is small or even negligible.

Basic Hardware Requirements of the Measuring Microscope:

Lens Requirements:
For microscopic measurement, it must be ensured that the image surface of the objective lens is flat. Optical microscopic measurement is actually to measure the image of an object. The image must overcome the curvature of field brought about by the objective lens and the image distortion caused by astigmatism so as to make the measurement more accurate. Therefore, for microscopic measurement, plan objective is recommended; for large-area long-distance measurement, the impact of perspective error also needs to overcome, for which, telecentric objective lens should be used.
For microscopic measurement, single light path microscope is generally used, such as metallurgical microscope; for continuous magnification, video zoom lens should be used. Because the two optical paths of the dual light-path stereo microscope have an angle of 12 degrees, on each optical path there has actually a 6 degree inclination angle from the vertical angle, in such a case, the measurement will cause error.
If the microscope is continuously zoomed, the main multiple points that need to be zoomed in should have magnification detent.

Light Source Requirements:
The light source for microscopic measurement should be uniform on the image plane of the field of view, and the bottom light should preferably use parallel light to make the outline and feature points clear. In theory, for microscopic measurement, it is best to use monochromatic light to reduce the effect of chromatic aberration, and therefore red light with the longest wavelength in the visible light is often used in measurement.

Platform Requirements:
Using optical measurement platform, it is possible to measure some large objects that exceed the microscope's field of view, and can achieve an accuracy of micron or even much smaller. The platform requires that the table plane should be of sound flatness, and maintains stable and leveling during movement. Moreover, the platform needs to have good rigidity, is not deformed or displaced itself, ensuring repeated measurement accuracy.

Other Simple Measurement Methods:
With the simple mechanism on the microscope, simple measurements and calculations can be performed on some observed objects that are not easy to use contact measurement. In addition to eyepiece reticle and objective micrometer measurement that we are familiar with, there are also other simple methods: for example, using the scale on the microscope stage, its accuracy can reach 0.1mm, which can measure the length of the measured object and roughly calculate its area; Using fine-tuning hand wheel mechanism of the microscope, calculate the height of the object to be observed by converting the fine-tuning number of revolutions into focusing stroke; using the rotating stage and the goniometer eyepiece, measure the angle etc.

Calibration:
Since the measurement is performed under the microscope on the image after the object is enlarged, it is therefore necessary to add a scale on the observed object so as to determine the actual size. The scale of a general microscope is called microscope micrometer, used to compare the actual size of the object or, as a scale6, to record to the measurement system.
Generally, the reticle measurement on the eyepiece of the microscope is between 0.2 μm ~ 25 mm, of which 0.2 μm is the resolution of optical microscope, and 25 mm is the maximum diameter of the microscope field of view. The effect of the magnification should be subtracted from the measured dimensions. Or for the eyepiece reticle, it is necessary to coordinate with the objective micrometer to calibrate under the microscope, convert the grid value on the eyepiece reticle to the length on the objective micrometer, and then measure.
In the XYZ measurement platform, the error caused by the measurement in the horizontal and vertical directions of the platform and the error caused in the repeated positioning accuracy by the rigidity of the platform should all be calibrated.
For measuring microscopes and scales, the calibration of their system or measuring components is usually conducted by relevant agencies within a certain time frame to make the measurement more accurate.

On the Error of Optical measurement:
The reason for the error of measurement is multi-faceted. From the theoretical point of view, for rough measurement using eyepiece reticle to zoom in through the objective lens of the microscope, the influence of the error of system magnification is relatively large, and because of the geometric magnification error of the optical lens, the objective lens of ordinary microscope can achieve plus or minus 5%.
Measuring with a scale on the objective lens, the problem of error of the measurement result caused by the magnification error of the objective lens can be theoretically solved.
Measurement using mechanical platforms, regardless of the drive and measurement scale used, aside from the theoretical error caused by the depth of field of the objective lens, it mainly depends on the measurement reading mechanism, such as gratings, micrometers and dial gauges etc. However, the rigidity of the platform, the flatness of the platform surface, and the level of platform movement will still affect the measurement results. Therefore, finding the problem can improve effectively the accuracy requirements when using even a very economical equipment system.

Video Zoom Lens

Video zoom lens, refers to microscope that has only one set of imaging optical paths. It can be considered as a set of dual optical path stereo microscopes. The magnification and multiple range of video zoom lens are usually the same as those of a stereo microscope, but because the objective lens is one, its optical imaging is flat, not stereoscopic.

It has been observed that as most of the parametric features are close to stereo microscopes, video zoom lens is then classified as stereo microscope. In fact, it lacks the most important "stereoscopic" imaging features. Compared with other compound microscopes such as biological metallurgical microscopes, the total optical magnification of video zoom lens is generally below 40X, which is the coverage of low magnification range that these microscopes do not have.

Most of the video continuous zoom lens is to observe the electronic image, not through the eyepiece, but through the camera.
Video zoom lens can have relatively more objective lens and photographic eyepiece multiples for selection. At the same time, video zoom lens can also be designed as parallel light so as to add even more configuration accessories, such as observation eyepieces, aperture diaphragms, coaxial illumination light sources, reticles, and nosepieces that can change the viewing angle and direction, etc.
Regarding accessories of video zoom lens such as the stands and light source etc., generally, all accessories of stereo microscope can be used. Therefore, video zoom lens combination is flexible, compact, with strong adaptability and low cost, suitable for use in industry, especially extensively used in the electronics industry.

Video Microscope

Video microscope, also known as TV microscope, is a microscope that converts an optical image into a video image. Typically, for video microscope, it is an analog camera that displays an image on a display or on a projection.

Digital Microscope

Digital microscope is the general term for microscope that can convert an optical image into a digital image, and usually does not specifically refer to a certain type of microscope. It should be noted however that most microscopes can be mounted with cameras and display devices to change to digital microscope.
Microscopes in the visible range, from the digital imaging point of view, all use CCD or CMOS sensors to image the optical signal as an electric signal on a computer or display. However, the difference between various kinds of digital microscopes mainly comes from the optical microscope itself, so it is necessary to look at the imaging effect and function of the optical part in order to select the type of digital microscope.

From the classification point of view, digital microscopes can be divided into: digital biological microscopes, digital stereo microscopes, etc. It should be noted that due to the variety of lenses, ordinary lenses or microscopes, if mounted with a digital camera, can all become a digital microscope.

At present, the trend of digital microscopes is not only to present simple digital images, but to collect, process and analyze images through back-end software, especially for image measurement, comparison, judgment, and large-format scanning and splicing, and three-dimensional synthesis and so on, these aspects have been widely developed and applied.

Portable Microscope

Portable microscope is the general term for microscopes that are simple in design, easy to carry and convenient for field observation. It usually does not refer to a certain kind of microscope.

Portable microscope is simple in design, but also like a microscope, there is at least one eyepiece and one objective lens, or is imaged by a camera, and has a stand and focusing device. Most of them can also be connected to a camera or an eyepiece camera, and then connect the monitor or store digital images.
Portable microscope generally adopts hand-held operation, and has simple configuration, fixed working distance, convenient for quick observation. Generally, portable microscope has a light source with a battery, which is convenient to carry to work place and field work, and is suitable for application of various industries and scenarios.

Gemology/Jewelry Microscope

Gemology/jewelry microscope is a microscope used to observe some of the invisible details on the surface and inside of jewels, gems, and various crystals when observing.

The surface features of jewellery, include scratches, breakage, color circles, etches, cleavage, cracks, split faces, polish, etc.; internal features, include the types of contents, the inclusions, growth lines, double crystal lines, textures, ribbons, and the doubling of the rear facet edge of the gemstone etc. For these features, it is very necessary to use gemology/jewelry microscope for observation and identification, and it has also an extremely important application in diamond grading, making it an essential instrument for gem identification.

For general jewellery observations, the defects and features after 10X magnification are considered the basis for economic evaluation. For jewelry microscope, stereo microscope is generally used, with a magnification of 10-80X or higher, and more detailed features can be seen. According to the characteristics of jewelry observation, jewelry microscope requires large depth of field, which can present the diamonds, jewelry interiors and their polyhedral structure, with true color reproduction effect.

Due to the different types of gemstones being observed, jewelry microscope needs to be matched with a variety of light sources and illumination forms. For lighting, usually full-color light is used, its continuous spectrum reflects the true color of the jewelry, and can achieve good observation effect for transparent, translucent and opaque object. The lighting methods of gemology microscope mainly include:
Reflective illumination: use the reflector lamp above to observe opaque or translucent objects, as well as the surface features of the gem, such as the ports, cleavage surfaces, ribbons, and gemstone grinding etc.
Transmitted illumination method: the transmitted light at the bottom is used to observe the internal features and defects of the gemstone. Usually, the bottom light is a diffuse reflection light source with dark field illumination, and there is a switch button, in the center of the bottom light, there is a black disc "light block", used to switch the light and dark field of view conversion of the bottom light.
Transmitted bright field illumination: the transmitted light can penetrate the interior of a gemstone. Against a bright background, details within the jewellery such as inclusions, textures, growth lines and ribbons can be seen clearly.
Transmitted light field dark illumination: after the bottom light is blocked by the "light block", it cannot directly enter the field of view of the objective lens, forming a diffuse reflection illuminating the gem around it, which is convenient for observing the inclusions, cracks and growth lines of the gemstone, and seeing the details that are not easy to find in bright field.
Spot light illumination method: adjust the aperture diaphragm (aperture) to a position close to the smallest suitable size, so that the bottom light is reduced into a dot shape, and the light penetrates from the bottom of the gemstone for illumination, so that the ribbon and the structural feature points of the gemstone are more prominent.
Horizontal illumination method: use a sidelight to illuminate the gemstone horizontally from the side, so that the gem dot-like inclusions, textures, and bubbles etc. present striking and bright image under the vertical direction light illumination.
Masking illumination method: use the bottom light bright field for illumination, insert an opaque light barrier in the field of view to increase the three-dimensional sense of the internal feature points in the black and white boundary of the light, which helps to observe the growth structure of the gem, such as the bending growth lines, double crystal lines, etc.
Scattering illumination method: use the bottom light bright field for illumination, place a tissue or other translucent material on the light source to make the light softer, which helps to observe the color gamut and the ribbon, especially to observe the diffusion treatment effect of the gemstone.
Polarized illumination method: under the bottom light source and the objective lens, a polarizer piece is added respectively to produce a polarizing effect, which can help to observe the interference effect, pleochroism and the optical characteristics of the gemstone.

For more precautions for use of gemology/jewelry microscopes, please refer to the Stereo Microscope on the BoliOptics website.

Surgical Microscope

Surgical microscope is a stereo microscope used for microsurgery, diagnostic treatment, observation, and research and other different functions of humans and animals under the microscope.

An surgical microscope has an optical system for observation, including an eyepiece, an objective lens, an objective lens zoom set, and lighting, stands, and electrical components, and its accessories are configured according to different needs.
The magnification of the surgical microscope is generally 8-20X. Compared with the stereo microscope, it has special requirements of large field of view, large depth of field, and long working distance, characterized by compact structure, small size and flexible operation.
Surgical microscope typically has flexible, large-space moving stands and electric controls.

For more precautions for use of surgical microscope, please refer to the Stereo Microscope on the BoliOptics website.

Microscope Eyepiece Tube

Microscope eyepiece tube, is also called eyetube, or microscope observation tube.
Microscope eyepiece tube, usually referred to the microscope eyepiece tube and the part of the connecting body, which, for some, is attached to the body, and for some others, separated from the microscope. When separated, a screwdriver or wrench is required in order to secure it to the microscope body.
The eyepiece of the microscope is, sometimes, carried in the eyepiece tube, and fixed by screws, and for some, it is separated, to facilitate selecting and mounting eyepieces of different magnifications. When mounting, it needs to be mounted again upon the eyepiece tube.

Eyepiece

Eyepiece is also called ocular.
Eyepiece is a visual optical device that is used to observe an image formed by an objective lens after magnification.
Eyepiece can magnify the real image obtained by the magnification of the objective lens to form a clear and erect virtual image at the least distance of distinct vision (LDDV). For aberration, eyepiece is usually composed of several lenses that correct the residual aberrations produced during imaging by the objective lens. Usually, eyepiece has a relatively larger field of view and angular magnification.

The eyepiece is provided with a diaphragm in the middle of the upper and lower lenses, or at the lower end of the lower lens, wherein micrometer, reticle, pointer and other accessories are mounted.
On the eyepiece there is engraved with the following marks: eyepiece type, magnification, field of view number, and the like. For example, eyepiece is engraved with PL10X/22; PL represents plane eyepiece, or flat-field eyepiece, 10X is the magnification, 22 represents the field of view, and the glasses mark represents high eyepoint eyepiece, and C represents compensating eyepiece.
Generally, the outer diameter of the eyepiece of a compound microscope is 23.2 mm, and stereo microscope can have a much larger field of view diameter because of its low magnification, so the outer diameter is mostly 30 mm (or 30.5 mm).

The resolution capability of the microscope is determined by the numerical aperture of the objective lens, while the eyepiece plays only the magnification role. Therefore, for structures and details that cannot be distinguished by the objective lens, the eyepiece still cannot distinguish even if it is magnified again.

Objective

The objective (lens) is the first set of optical systems that image the object being observed, and is also the most important imaging component in the microscope.
Depending on the application, objective is usually classified into the following categories:

Biological Objective
Metallurgical Objective
Phase Contrast Objective
Polarizing Objective
Dark/Bright Field Objective
Stereo Objective
Monocular Video Microscope Objective
Infinity-Corrected Long Working Distance Objective
NIR Objective
NUV Objective
UV Objective
Telecentric Objective Lens

Some objectives are mounted directly on the microscope body, some separate from the body and are installed when needed.
Different types of microscope objectives are generally not interchangeable. However, when ofthe same type and parameter design the same or similar, the objectives of different models and manufacturers are interchangeable, provided that attention shouldbe paid to the change in magnification, working distance, field of view and image quality.

Usually, on the objective outer casing, there are signs of the following parameters:
Objective Magnification: for example 10X, 40X
Numerical Aperture (N.A.): for example, /1.30
Objective Immersion Media: Oil represents oil, W represents water, and Glyc represents glycerin
Mechanical Tube Length and Objective Cover Glass Thickness: the two parameters are usually written together and separated by /. The finite mechanical is usually 160, 195, etc., and infinite is represented by "∞"; objective cover glass thickness (thickness / mm) is expressed after/, for example /0.17; for specimen that does not use objective cover glass, it is represented by 0, for example, "/0"; for those that do not use objective cover glass or the objective cover glass thickness is smaller than 0.17, it is represented by "/-".
Phase Contrast Objective: represented by PH, for example, PH2, the digit after PH represents the associated ring diaphragm.
Polarizing Objective: represented by POL.
Plan Objective: represented by PLAN or PL
Achromatic: generally, achromatic objective does not require identification
Apochromatic: represented by APO
Long Working Distance: represented by L
There are also objectives that are unique in magnification and medium, and their difference is indicated by color circle.
For objectives that do not have mark, it is necessary to refer to the microscope body for judgment, or refer to the product manual.

Usually, the objective has very fine mounting threads. When there is a need to install the objective /objective frame, be careful to install it. Align the nosepiece installation position, keep it completely “flat”. When it is blocked, remove it and reinstall it. Do not force it in.

Note: although between different manufacturers, some objectives can be used universally, they may still bring magnification error and image quality degradation.

Scope Body Parts

Nosepiece, also known as revolving nosepiece, can be mounted with several objective, and one of which in turn can be switched to the microscope optical axis for use.
Nosepiece has different configurations, namely, single, triple, quadruple, and quintuple. Each objective has a ball buckle at its position to ensure that the objective is in the exact fixed position of the optical axis. Since any one set of objectives has the same parfocal distance, so when the objective is switched between high and low magnifications for observation, it is almost unnecessary to perform again the focusing operation.
Nosepiece can be divided into two types, namely, inward nosepiece and outward nosepiece, depending on the positional direction. After switching, the tube of inward nosepiece is inclined to the side of the microscope body, which can save people's operating space and prevents it from hitting the lens.

In general, after the objective is mounted onto the nosepiece, no special coaxial processing is required. If necessary, remove the nosepiece, and adjust the position of the end point screw on the dovetail rail behind the nosepiece. If the objective is still off-axis, adjust the optical axis of the condenser to match the optical axis center of the objective.
In the use of microscope, if one set of objective cannot be parfocal, there are many reasons for the problem, but it may be that the nosepiece or the set of objective itself cannot guarantee parfocalness due to problems of processing precision. In this case, after confirming that the high and low magnifications of the objectives at both ends are in focus, adjust the objective of the middle magnification, and usually try to add a thin "shims" to correct.
For normal switching of the objective, it is necessary to push the nosepiece instead of pushing and pulling the objective to prevent the objective and the nosepiece from deviating from the optical axis or loosening, so as to avoid image out of focus or damage.

Microscope Stand

Microscope stand have many options depending on the needs, especially stereo microscope stand, there are several factors to consider before choosing:
Stability: microscope stand is used to prop up the microscope body. The stand should be selected according to the size of the microscope mainframe. The stability of the stand determines the stability of the microscope in use, and its various adapters and screws must be tightly locked.
Volume size: limited by the working environment and space of the workbench.
Workspace and scope: the size of the workspace of the object being observed and the height of the object being observed should be considered.
Choice of lighting: some stands are equipped with a light source, but some are not, depending on whether there are conditions to add additional lighting.

Operational requirements:
1. Install the stand as required.
2. Arrange a reasonable fixed position for the stand.
3. Carefully tighten the microscope mainframe.
4. Arrange the location of the additional light source reasonably, and place the electric wire in a position that does not interfere with the work.
5. Connect the various kinds of peripheral devices, such as cameras, monitors, computers and so on.

Microscope Stage

Microscope stage is usually located under the objective lens of the microscope to place the object to be observed. Usually, it is equipped with mechanical motion devices, and is moved and positioned in XYZ three directions or rotates or tilts around the Z axis and other functions.
Microscope stage usually has a function of moving in the XY horizontal direction, and is required to be perpendicular to the optical axis of the microscope Z direction in the XY horizontal direction.

Illuminator

The conditions of different illumination of the microscope are a very important parameter. Choosing the correct illumination method can improve the resolution and contrast of the image, which is very important for observing the imaging of different objects.

The wavelength of the light source is the most important factor affecting the resolution of the microscope. The wavelength of the light source must be smaller than the distance between the two points to be observed in order to be distinguished by the human eye. The resolution of the microscope is inversely proportional to the wavelength of the light source. Within the range of the visible light, the violet wavelength is the shortest, providing also the highest resolution. The wavelength of visible light is between 380~780nm, the maximum multiple of optical magnification is 1000-2000X, and the limit resolution of optical microscope is about 200nms. In order to be able to observe a much smaller object and increase the resolution of the microscope, it is necessary to use light having a much shorter wavelength as the light source.
The most commonly used technical parameters for describing illumination are luminescence intensity and color temperature. Luminescence intensity, with lumen as unit, is the physical unit of luminous flux. The more lumens, the stronger the illumination. Color temperature, with K (Kelvin) as unit, is a unit of measure indicating the color component of the light. The color temperature of red is the lowest, then orange, yellow, white, and blue, all gradually increased, with the color temperature of blue being the highest. The light color of the incandescent lamp is warm white, its color temperature is 2700K, the color temperature of the halogen lamp is about 3000K, and the color temperature of the daylight fluorescent lamp is 6000K.

A complex and complete lighting system can include a light source, a lampshade or lamp compartment, a condenser lens, a diaphragm, a variety of wavelength filters, a heat sink cooling system, a power supply, and a dimming device etc. Select and use different parts as needed. Of which, selection and use of the illuminating light source is the most important part of the microscope illumination system, as and other components are designed around the illuminating wavelength curve and characteristics of the illuminating light source.

Some of the microscope light sources are pre-installed on the body or frame of the microscope, and some are independent. There are many types and shapes of light sources. Depending on the requirements of the microscope and the object to be observed, one type or multiple types of illumination at the same time can be selected. In addition, the whole beam and band adjustment of the light source, the position and illumination angle of the light source, and the intensity and brightness of the light all have a great influence on the imaging.
For microscope imaging, a good lighting system may be a system that allows for more freedom of adjustment. In actual work, such as industry, too many adjustment mechanisms may affect the efficiency of use, therefore choose the appropriated configured lighting conditions is very important.

Coupler and Camera Adapter

Coupler or camera adapter, is also called photo eyepiece, CCTV adapter, CCD adapter, camera adapter, digital camera adapter, and camera adapter etc.

Coupler is an optical imaging lens that uses mechanical adapter device to connect the camera to the microscope, and project the image onto the camera's target through the adapter.
Coupler/C-mount adapters have different magnifications to capture images of different magnifications and field of view. In optical imaging, optical parameters such as chromatic aberration, distortion, and field curvature are also to be considered to ensure image quality. At the same time, for some other couple/C-mount adapters, factors such as the position and angle of the camera are also considered to suit the needs of the observational environment.

Microscope Camera

Microscope camera is also called camera, video-camera, industrial camera.
Camera is a device in which a microscope or lens converts an optically magnified image into an electrical signal and displays its image on a terminal display.
According to the difference of signal acquisition and output modes, camera can be divided into analog camera and digital camera; according to the difference of image sensor, camera can also be divided into CCD camera and CMOS camera.
For cameras used in microscopes, the most important requirement is to display images on the terminal display. Different cameras also have image acquisition, storage and processing functions.

Film Ruler

Scope of Use of the Point Gauge and Line Gauge of the Film Ruler:

They are usually used for product measurement, measuring size, angle and area, etc., their measurement are intuitive, size are accurate, and easy to use.
They are used for product exterior inspection and comparison, to compare part size, positional deviation, check the size and position of silk screen printing, and determine whether the stains, cracks, scratches, grayscale and debris exceed the baseline.
Through the standard setting of the exterior level, the inspector can standardize and unify the inspection standard of the product, and reduce the inspection judgment error of the product.
Suitable for textile, printing, plastics, PCB, LCD, optoelectronics, communications, electronic components, machinery and other industries.

How to Use Comparison
First, based on the inspection standard, determine a certain point on the point gauge as the standard point.
When inspecting a tested point, first determine its approximate size and shape, then find the standard point on the point gauge, use this standard point to cover the tested point, if it can be covered, it will allow to pass, if it is not allowed to cover, it can't pass.

Film Rule Inspection Requirements:
1) Exterior Inspection:
The external dimensions should conform to the parameters, the glass is transparent, free from mottling, impurities, and the edge is blunt and there is no chipping.
The markup font is clear, no defects, and the tick marks is clear and unbroken.
It is required that the exterior will have no wear marks, dirt, creases, and no printing blur or flashing.
It is required that the packaging must not be folded, squeezed and come into contact with contaminants, keep the packaging materials dry, the packaging materials should be clean and free of stains, the packaging box will have no deformation and wrinkles, and the logo is neat.

2) Inspection accuracy:
Usually a monocular microscope 480X, a stereo binocular microscope 90X are used for testing.
The accuracy of the printer: 0.1mm, due to the influence of printer and material accuracy, the larger the size, the smaller the influence of manufacturing error; the smaller the size, the greater the influence of manufacturing error.
0.01--0.05mm, the error value is very large, so the tick marks value below 0.05mm is only used as a reference value, not as a measured value.
0.05--0.5mm, low precision, but can be used for reference;
0.5--0.75mm, error is less than 3%, can be used for general testing
0.8--1 mm or more, relatively high precision, error is within 0.01mm, can be used for measurement.
In short, the film ruler can be used to quickly test and control the quality of the product parts with low precision and high output; the advantage is faster comparison and simple operation.

Precautions
Calibration Certificate for this product is not included.
It is not recommended to use a device that is out of range or magnifying multiple to calibrate these gauges.

Note: Do not fold or rub the surface. When it is found that there are foreign objects or dirty marks on the surface, you can wipe it with cotton cloth dipped with alcohol. Do not wipe with water.
Specific products can be customized to suit your needs.

Microscope Body

The microscope body refers generally to the body of the instrument. This part usually refers to the body between the eyepiece and the objective lens, or the intermediate main body connection system. The microscope of this part mostly refers to the body of the stereo microscope, but there is no clear component range definition, and the relevant parts need to be confirmed according to the parameters of the specific product.
The body of the microscope is between the eyepiece observation tube and the objective lens of the microscope, it is the location to add various kinds of "Intermediate Pieces", including lighting systems, zoom systems, and so on. The finite microscope system needs to be designed as one, and infinite microscope system can add and subtract components at any time during the process of use as needed.

Binocular Zoom Body

Binocular zoom body is the main body of a stereo microscope that has continuous zooming functions and observes with two eyepieces.
This body usually needs to be placed on a microscope stand for use. Generally, a variety of eyepieces and objective lenses with different magnifications can be selected. A high-end stereo microscope usually has a wide range of accessories for selection.

Trinocular Zoom Body

Trinocular zoom body is the main body of a stereo microscope that has continuous zooming functions. In addition to the two eyepieces for observation, there is a third optical path (image port), which is usually a set of optical paths borrowed from the microscope for connecting to the camera to facilitate the observation with the display or connecting to a computer. Usually, the third ocular of the body can be configured with different photo eyepieces, or other interfaces to connect to different webcam, cameras and so on.
This body usually needs to be placed on a microscope stand for use. Generally, a variety of eyepieces and objective lenses with different magnifications can be selected, and high-end stereo microscope usually has a wide range of accessories for selection.

Binocular Dual Power Body

Binocular dual power body refers to the main body of a stereo microscope with two objective lens magnifications. When performing magnification-shifting, two different magnifications can be obtained.
When the body needs other different magnifications, it can also be solved by adding or changing the objective lens/auxiliary objective lens, or by changing the eyepieces of different magnifications.
Dual power stereo microscope mostly uses 10X, 20X, 30X, 40X combinations of two kinds of magnifications. When the magnification is greater than 40X, the image is close to the plane effect, and the stereoscopic effect is relatively poor.
Dual power stereo microscope has a simple structure, high reliability and low cost, it is a kind of stereo microscope that can satisfy stereo image applications.

Trinocular Dual Power Body

Trinocular dual power body refers to that there is an image port on the body of the dual power stereo microscope, which can be connected to the webcam for viewing or observing with the display, or connecting to the computer. Usually, the image port of the body can be configured with different photo eyepieces, or connect to different webcam or cameras etc. through other interfaces.

Binocular Multiple Power Body

Binocular multiple power body refers to that the objective lens of the stereo microscope has a set multiple of more than two, and when multiple-shifting is performed, a multiple different magnifications can be obtained.
When the body needs other different magnifications, it can also be solved by adding or changing the objective lens/auxiliary objective lens, or by changing the eyepieces of different multiples.

Trinocular Multiple Power Body

Trinocular multiple power body refers to that, in addition to the binocular multiple power body of the stereo microscope, there is also the third (image Port), which can be connected to a webcam for viewing or observing with the display, or connecting to the computer. Usually, the third (image port) of the body can be configured with different photo eyepieces, or connect to different webcam, cameras etc. to other interfaces.

Monocular Fixed Power Body

Monocular fixed power body refers to the microscope that on its body there is only one eyepiece for observation, and there is only one magnification. When it is necessary to change the magnification, it can be achieved only by replacing the objective lens or eyepiece.

Fixed Power Body

Fixed power body generally refers to binocular stereo microscope that has only one fixed magnification. When it is necessary to change the magnification, it can be achieved only by replacing the objective lens or eyepiece.

Binocular Parallel Zoom Body

Binocular parallel zoom body is the body of the parallel light stereo microscope module, which has at least one intermediate zoom body, including a tube lens, for continuous change of the magnification.
There are also other bodies that include a binocular viewing tube with an eyepiece and an objective lens, which need to be determined based on specific parameters.

Trinocular Parallel Zoom Body

In addition to the binocular parallel zoom body, trinocular parallel zoom body has also a parallel trinocular module, usually added between the microscope body and the viewing tube for connecting the microscope camera or other optoelectronic components.

Multi-Viewing Parallel Zoom Body

By way of assembly of beam splitting prism or an optical bridge, two or more parallel zoom microscope body and the viewing tube are grouped together, wherein one person operates for viewing or observation by multiple people for teaching and demonstration effects, such as surgery, factory under lens operation, etc. Multi-person viewing microscope has the same real-life scenes as operation under the microscope.

Parallel Fixed Power Body

Parallel fixed power body is the body of the stereo microscope of the parallel light module. It has at least one intermediate body, including the tube lens. The magnification of the body is fixed, or may also have two or more magnifications.
There are also other bodies that include a binocular viewing tube with an eyepiece and an objective lens, which need to be determined based on specific parameters.

Video Monocular Zoom Body

Video monocular zoom body is a zoom body that has only one set of optical paths, and it is also the body of the video continuous zoom.
The upper end of the microscope body can be connected to the standard C-interface photo eyepiece, and then connected to the microscope camera; the lower end is the objective lens, and the objective lens of parallel structure is generally separated from the body, whereas the microscope body of finite structure is combined with the objective lens.
Some bodies of microscope have also a light source coaxial illumination device.

Video Monocular Fixed Power Body

Video monocular fixed power body is the microscope body that has only one set of optical paths, its magnification is fixed. Its upper end is connected to the C-interface standard photo eyepiece, and the lower end to the objective lens

BGA Microscope Body

The BGA microscope is a digital instrument specifically designed for inspecting BGA encapsulation. Its primary function is to facilitate visual inspection of BGA encapsulation solder joints, enabling detection and analysis of their quality and condition. Additionally, it is suitable for inspecting semiconductor components, LCD screens, and connector pins. Featuring a rotating capability and a built-in 45° prism, it offers a comprehensive perspective for detailed observation. Equipped with an HD camera, the microscope provides high-quality 3D real-time images, surpassing traditional optical microscopes in terms of image quality, depth of field, and functionality. It can be used handheld or mounted on a stand.

Centering Telescope

Also known as the centering eyepiece, or the cross reticle eyepiece.
It is an eyepiece with a cross reticle, usually 10X. The cross reticle is calibrated and the cross is at the geometric center of the imaging surface of the eyepiece.
The centering eyepiece is primarily used to adjust and verify the center of the optical axis of the microscope system, such as the centering action of the rotating platform for a polarizing microscope.
The centering eyepiece can also be used to detect whether the optical axis of the microscope is at the center position, and whether the two optical paths on the left and right of the stereo microscope have double image, and so on.

Eye-Level Riser

Adding a module onto the microscope allows the microscope to increase the height of the eyepiece, to facilitate the comfortable viewing of the eyes of people of different heights, which is helpful especially for people who use the microscope for a long time.
This module height can only be increased on a parallel optical microscope without changing the imaging of the microscope.
For separate stereoscopic microscope or greenough, usually a conversion tube is added onto the microscope stand to raise the microscope.

Objective Convertible Adapter

Convert the thread size of the objective so that it can be used on different microscopes.

Objective Angle Converter

Objective angle converter can change the viewing direction of the optical axis of the objective, and it is possible to observe at a suitable angle of the object, such as 90 degrees, 45 degrees, and the like. After adding the angle viewer, the working distance of the original objective will be reduced accordingly.
Observing in the oblique direction is suitable for observing the surface of some objects with "height". For some special positions, it is much easier to see the whole picture. In the electronics industry, the solder joints and solder fillets of electronic components can be seen more clearly.

Ring Adapter

Ring adapter is used for the nosepiece under the stereo microscope or the circular interface under the microscope objective, with appropriate threads to engage.
The main function of the ring adapter is to connect the ring light. Some microscopes have grooves on their nosepiece, which can directly clamp the ring light, but it can easily damage the surface of the nosepiece of the appearance of the microscope, so it is more suitable to use an interface.
Some ring adapters have one or two grooves on them, and they are used to clamp screw of the ring lights.
There are also ring lights that are clamped on the Barlow lens of the microscope. If the lower end of the Barlow lens is threaded, an additional ring adapter can also be attached to clamp the ring light, so as to protect the surface of the objective.
Usually, the ring adapter has very fine mounting threads. When the objective/ring adapter needs to be mounted, the mounting should be careful. Align the position of the nosepiece for installation to keep it completely “flat”. When it is blocked, remove it and install again, do not force it in.

Post Stand

Post stand generally has relatively tall post. When the focus is adjusted, the focusing mechanism can slide up and down the post, the microscope is thus placed in an approximately focused position, and then the focusing mechanism makes fine and accurate adjustment. This kind of stand can move quickly, and is suitable for viewing objects with a higher height and bigger volume.
After the microscope is mounted, the microscope imaging center needs to be aligned with the center of the platen.
The focusing mechanism button on the post must be tightened to lock the guard ring device, and the microscope should be prevented from loosening and shaking when working. When it is necessary to adjust the height, hold the microscope and the focusing mechanism with one hand, then release the knob, adjust it to the proper position, lock the knob, then top the guard ring to the lower position of the focusing mechanism, and lock it tight. In particular, avoid accidental dropping of the microscope due to gravity, thereby damaging the microscope and the objects below.

Track Stand

Throughout the focusing range, the track stand moves up and down along the guide rail through the focusing mechanism to achieve the purpose of focusing the microscope. This kind of structure is relatively stable, and the microscope is always kept moving up and down vertically along a central axis. When the focus is adjusted, it is not easy to shake, and there is no free sliding phenomenon. It is a relatively common and safe and reliable accessory.
The size of the stand is generally small, flexible and convenient, and most of them are placed on the table for use, Therefore, together with the post stand, it is also called “desktop or table top stand".
With regard to the height of the stand, most manufacturers usually do not make it very high. If the guide rail is long, it is easy to deform, and relatively more difficult .

Boom Stand

Boom stand is also called universal stand.
It is a relatively large pole type stand. The height and length of the stand are big, and it can be freely adjusted in height, length and various angles. Its large weight ensures stable support and occupation of large space, but it can make the microscope free to move in a wide range with convenience. Boom stand is suitable for observing large objects.
The direction of boom stand is flexible, and when in use, various kinds of positions and methods can be adopted, such as front, side, and tilt etc., to facilitate the layout of the workbench. On the side of the crossbar of the boom stand, a 5/8-inch connecting hole is generally left for connecting various focusing mechanisms and microscopes.
The base of the boom stand usually only plays a fixing and supporting role. Under the observation of the microscope, it is an empty workbench, which can be used to place various platforms, work operating surfaces, and tools, etc., and can be freely combined into different working positions. When the base is large, the object to be observed can also be placed.
In industrial places, most of the working positions are fixed. Sometimes, in one working position, a lot of tools, equipment and instruments need to be placed.. Because the microscope is relatively large in size and takes up also a relatively bigger space, and not convenient to move back and forth, therefore for purpose of use, the boom stand can be placed in an appropriate position, and does not need to occupy the most commonly used work tables. When in use, the microscope can be moved over, and pushed to the side when not in use. This is very suitable for use in electronics factories, installation and maintenance, medical and animal anatomy, archaeology and other industries.

Boom stand generally does not have a fixed focusing device, and you can choose a variety of flexible accessories.
Because the stand needs to ensure flexibility, therefore there are many locking buttons in all directions. In any time after adjustment, it must be ensured that each knob is in a locked state to avoid sliding, tilting and flipping of the microscope, thereby damaging the microscope and the items on the workbench.

Dual Arm Stand

Dual arm stand is also called double bar stand, or ball bearing boom stand.
The method of use of dual arm stand and most of its parameters are mostly the same as that of the boom stand. The difference is that the cross arm has two rods, and is held by one set of bearings, so that the two cross arms can be freely pulled and moved, and they are vertical and cannot be tilted left and right, making it more free and stable than the use of the dual arm stand in the horizontal direction. It is especially suitable for users who need to frequently push and pull, observe and adjust the position in horizontal direction.

Flexible Arm

Flexible arm is an arm or stand that imitates the human arm. It is a combination of several mechanical arm joints to complete the horizontal and vertical movement and freely adjust the focus position of the microscope. Flexible arm allows the microscope to move flexibly and freely over a wide range, and is also suitable for viewing larger objects.
The fixing method of the arm is usually optional, with strong interchangeability. Below the observation of the microscope there is an empty workbench, which can be used to place various kinds of platforms, work operating tables, tools, etc., and can be freely combined into different working positions.
In industrial places, most of the working positions are fixed. Sometimes, a lot of tools, equipment and instruments need to be placed in one working position. Because the microscope is relatively large in size and takes up also a relatively bigger space, and not convenient to move back and forth, therefore the flexible arm can be placed in a flexible position, and does not occupy the most commonly used workbench. When in use, the microscope can be moved over, and pushed to the side when not in use. This is very suitable for use in electronics factories, installation and maintenance, medical and animal anatomy, archaeology and other industries.
Flexible arm generally does not have a fixed focusing device, and you can choose a variety of flexible accessories.
When adjusting the height of the flexible arm, you need to use both hands at the same time, with one hand holding the microscope or the forearm of the stand, and the other adjusting the adjusting screw or spring mechanism that looses/tightens the arm. When releasing, pay attention to avoiding sudden sliding down.

Because one needs to ensure the flexibility of the arm or stand, there are many locking buttons in all directions. After the necessary locking buttons are adjusted, it must be ensured that each knob is in locked state to avoid sliding, tilting, and flipping of the microscope, thereby damaging the microscope and the items on the workbench.

Flexible arm has a mechanism of the hydraulic spring for adjusting the pre-tightening tension. When different microscopes weigh differently, these flexible arms can be adjusted to make the microscope more stable.

Jewelry Stand

Jewelry microscope stand is a special stand designed to detect jewelry, diamonds, etc. A jewelry stand is usually equipped with the following several light sources and devices:
Upper light source has both natural light of a halogen lamp and fluorescent lamp. The fluorescent lamp is usually a "full-wave band" fluorescent lamp. The use of a natural light with continuous wave band can ensure the effect of observing jewelry and diamonds, and is consistent with the effect color seen under daylight.
Lower light source: diffuse reflection light with dark field equipment is often used, and some advanced stand are also equipped with iris diaphragm. Uniform illumination can eliminate reflection and stray light to facilitate observation of details of the jewelry or diamond.
Jewelry clips are used to clip or clamp jewels and diamonds.

Horizontal Observation Stand

Horizontal observation stand is the microscope stand that can adjust the microscope to horizontal direction for observation.

The side of the object can usually be seen, such as inside of the side wall of a test tube filled with liquid.
For the cross-section of some fiber and cable joint parts, it is not easy to observe in the longitudinal direction because the pipeline is relatively long. At this time, horizontal placement is detected by the horizontal observation stand, which is relatively convenient. For example, horizontal observation stand is applied in the industry for detecting fiber joints.
In industrial inspection, when testing the high and low levels of some parts, horizontal placement methods can also be used for comparison and inspection.

Vertical/Horizontal Flip Stand

Vertical/horizontal flip stand is the microscope stand that can adjust the angle and position in both horizontal and vertical directions.

Lighting Angle Stand

Lighting angle stand is a kind of stand that can fix and adjust the incident angle and position of the light source. The angle and position of the incident light are related to the imaging effect when observing and detecting different objects.

Dual Stage Stand

On the microscope post and base, add a platform that can move up and down, so that the height of both the microscope and platform can be freely adjusted, and it is mostly applied on the stereo microscope stand.
This is an ergonomic design and application in the use of microscopes, mainly to facilitate the adjustment of the height of the person when using the microscope, to make it convenient and comfortable to observe for different heights and observation positions. In particular, in the scene and environment wherein the user needs to observe in a standing position, the object to be observed can be placed at a relatively high position, and people of different heights can freely adjust the height of the microscope and the platform.

E-Arm

Usually the universal joint is called E-Arm, i.e., Easy-Arm, also known as Universal Arm. Many people in the industry call it Bonder Arm, which refers to the components that connect the microscope on the COG Bonding Machine.
At the tail of the E-arm there is a standard 5/8 inch (0.625 inch, 15.875mm) connector. The connector can be moved freely in both horizontal and vertical directions, and can also be fixed at an angular position in the vertical direction to facilitate microscope observation from different angles.
E-arm can be connected to various kinds of microscope stands with 5/8-inch adapters, such as boom stand, flexible arm etc. It is also possible to connect various kinds of microscopes by adding or replacing different adapters. Note that, in general, these stands themselves are not directly configured with this E-arm, and separate purchase is necessary.

Inclinable Focus Drive

Inclinable focus drive is a kind of focus drive with a much higher focusing height. It increases the longitudinal focusing length of the focus drive, which is convenient for the microscope to observe in a wider range. Especially when observing objects with a particularly large height change, it is no longer necessary to repeatedly adjust the height of the large stand behind, so that the user operation can be more flexible and convenient.

Arbor

Arbor is a connecting rod between the microscope stand and the microscope focusing mechanism. The tail has a standard 5/8 inch (0.625 inch, 15.875mm) connector that can be moved freely in both the horizontal and vertical directions, and can be fixed at an angular position in the vertical direction for viewing from different angles using the microscope.
There is also fixed arbor that only serves as a connection, but it remains vertical during use and cannot be rotated.
The diameter of the arbor is different, and different focus rack can be connected, which in turn is connected to the microscope.
The arbor can be connected to a focus rack as a focusing mechanism, moving up and down to adjust the longitudinal working distance, which increases the longitudinal focusing length of the focusing mechanism, to facilitate observation from the microscope in a wider range. Especially when observing objects with extremely big changes of height, it is no longer necessary to repeatedly adjust the height of the large stand behind, which makes the user's operation more flexible and convenient.

Focus Rack

Focus rack is the focusing mechanism that connects the microscope, with one end connected to the post of the microscope stand to adjust the up and down movement of the microscope for focusing.
The front end of the focus rack can also be used to connect microscopes or cameras of different diameters by changing the scope holder.

Extension Bar

Extension bar can lengthen the working distance of the microscope stand vertical post. When observing relatively big and tall objects, or needing to stand to observe, holding the item with hand for quick observation usually requires a relatively high stand.
After installing the post of the body of the stand, unscrew the cover on the post, and connect the screws of the extension bar together.

Donut Adapter

Donut adapter is an adapter used to convert the scope holder of the microscope and the size of the microscope body. For different manufacturers and different types of microscopes, as well as different stands, their adapters are often different and not interchangeable. This type of donut adapter can be used to connect different microscope stands and microscope bodies, which is very convenient for interchange of different manufacturers and microscope models.
It is usually to use this adapter cable to fix it to the body of the microscope, which is equivalent to changing the fixed diameter of the microscope, and then placing it on the microscope stand.

Wall Mount Adapter

When the microscope is needed to be fixed onto the wall, use this wall mount adapter that is fixed onto the wall, especially when it is needed in operating the space for use, such as in hospitals, clinics, etc.
When installing the wall mount adapter, one must first confirm whether the wall is load-bearing, and whether the weight of the stand and the body is bearable.

Table Mount Adapter

Punch on the table, fix and install the microscope stand onto the adapter on the table.
Pay attention to confirming the material and thickness of the table in advance, and whether the adapter for installation can withstand the weight of the microscope and the stand.

Clamps and Stands

Base clamp is the clamp of the microscope stand that is clamped on the side of the desktop.
Pay attention to confirm in advance whether the material and thickness of the tabletop can withstand the weight of the microscope stand and the body.

Pneumatic/Flexible Arm Adapter

Light emitting diode is a type of semiconductor diode that can convert electrical energy into light energy.
Advantages: low operating current, low operating voltage, working voltage between 3-24V DC, so it is a safer power supply than high voltage power supply, especially suitable for weak electrical equipment.

Its electro-optical conversion efficiency is high (close to 60%), and its low power consumption, low heat, and energy consumption are reduced by about 80% compared with incandescent lamps with the same light efficiency, and about 40% less than the energy-saving lamp.
It is a kind of cold light with low temperature. As an illumination that is close to the observed object, especially the bottom, it may not interfere with and damage the observed object and the temperature environment.
LEDs are easy to dim, and its beam is concentrated. LED has two control modes, namely, constant current mode, and constant voltage mode. Most LEDs adopt constant current control, which can keep the LED current stable and extend the service life of LED lamps.
LED is also easy to select the color temperature of light, suitable for observing different objects. The energy band structure and the forbidden band width of the material can be adjusted by chemical modification methods to realize multi-color luminescence of red, yellow, green, blue and orange and, from red to blue, the color can cover the entire visible spectrum.
LED has long service life. LED's service life can reach 100,000 hours under the right current and voltage, and repeated switching on and off will not damage its service life.
LED has high brightness, even and stable illumination, fast response speed, start-up has no delay, and its response time is of the nanosecond level.
Given its small size, flexible structural position and combined application, each unit LED small piece is a 3-5mm square, so it can be made into various shapes of devices. It is safe, durable, shock and seismic resistance, with high reliability.
Energy-saving, environmentally friendly, LED is composed of non-toxic materials, unlike mercury lamps which contain mercury that can cause pollution, and LEDs can also be recycled.

In contrast, various kinds of traditional lighting has certain drawbacks:
Incandescent lamp: low electro-optical light conversion efficiency (about 10%), short service life (about 1000 hours), high heat generation temperature, single color and low color temperature.
Fluorescent lamp: electro-optical conversion efficiency is not high (about 30%), harmful to the environment (including harmful elements such as mercury, about 3.5-5mg / only), non-adjustable brightness (low voltage can not start to illuminate), has ultraviolet radiation, flicker phenomenon, start-up slower, and repeated switching on and off can affect service life, with also relatively bigger size.
High-pressure gas discharge lamp (mercury lamp): high power consumption, unsafe use, short service life, and many heat dissipation problems.

LED shortcomings: high initial cost, poor color rendering, discontinuous spectrum, not suitable for some special lighting industry applications, high power LED low efficiency, long-term use can gradually become darkened, and there is brightness and light decay phenomenon.

Honeycomb Optical Table Adapter

Honeycomb optical table adapter is the adapter that connect the microscope stand and the optical table. At this time, the stand uses the optical table as the base.
Honeycomb optical tables are usually available in two size standards, namely, the metric size standard, and the British system size standard (1X1", or 25X25mm). When selecting the adapter, attention should be paid to the size that adapter to the honeycomb optical table.

Lock Ring

Lock right is installed under the pole focusing mechanism. This ring needs to be placed tightly on to the lower part of the motion focusing mechanism.
This device has two functions:
First, when the body of the microscope is relatively heavy, the microscope and the focusing mechanism are protected by way of support and prevention from falling off, so that it does not fall down. However, it is still necessary to tighten the focusing mechanism, and one cannot completely rely on the support and protection of this device.
Second, is to determine the position of the lower limit of the focusing mechanism. When moving the focusing mechanism to reach this position, the lock ring does not allow it to exceed this position, thus avoiding bumping against the underlying object to be observed or the bottom plate of the stand because of misoperation or the sudden falling of the microscope.

Microscope Plate

According to different objects to be observed, the appropriate platen should be selected. The microscope plate materials include black and white, black and white finish; transparent glass, frosted glass, metal, etc.
Standard stands are generally configured with a suitable microscope plate, but different plates may need to be purchased separately.
Black and white microscope plate are made of general plastics, and the different backgrounds in black and white make the object more prominent.
Finish microscope plate eliminates reflections during observation.
Transparent glass plate is used when observing transparent or translucent objects, and the use of transmitted light source is to make the light penetrate the object to be observed as much as possible.
Finish glass plate, with its rough glass surface, can make the transmitted light more uniform and create a diffusing effect, avoiding exposure of the light shadow of the filament directly onto to the observed object.
Metal plate, relatively more solid, is more suitable when it is necessary to operate and cut.
Microscope plate is generally round shaped, on one side of the base there is a spring clip. When installing, align the plate with the clamp and push it in, and then press down the other end, so that the plate is smoothly embedded in to the circular card slot of the bottom plate.
When removing, grab the other end of the clip, push and lift up the plate.

Jewel Tweezers

Jewel tweezers are clips used to clamp jewels or diamonds. The spring clip at the front end can be freely opened and closed to clamp the jewel, the rear end is often fixed on the base, and can be freely rotated and stretched to observe the different positions and angles of the jewel. The commonly used wire gemstone clamps, have moderate steel property, strong clamping, and can reduce the light shielding of the gemstone waist, allowing comprehensive viewing of the gemstone in all directions

Honeycomb Optical Table/Platform

Honeycomb optical tabel /platform is to use standard honeycomb optical table/platform as the base of a microscope to facilitate the installation of various mechanisms on the base.
Honeycomb optical platforms are usually available in two size standards, namely, the metric size standard, and the British system size standard (1X1", or 25X25mm). When selecting the adapter of the microscope stand, attention should be paid to the size that adapter to the honeycomb optical platform.

XY Mechanical Stage

There are motion and positioning mechanisms in the XY horizontal direction.
In general, the XY stage needs to adjust the level of the stage, so that the stage plane and the main optical axis of the microscope Z direction are perpendicular.

XYZ Mechanical Stage

There are motion and positioning mechanisms in three directions in the XY two horizontal directions and the Z vertical direction.
The compound microscope stage generally has motion mechanisms in XYZ three directions. The Z-axis is mostly fixed with the microscope body stand, and can move along the Z-axis direction of the post for microscope focusing.
Most compound microscopes adopt such kind of design, and it is convenient to install the light source below for transillumination. This is a accuracy part, generally, it should not bear excessive weight, and maintain light and stable movement during use. Do not use excessive force at the extreme position to avoid damage to the stage rack, resulting in loosening and falling.
The independently placed XYZ stage is generally placed on the base of the microscope. Such a platform can withstand greater weight, generally a stereo or industrial microscope for viewing objects of larger volumes.

Fixed Mechanical Stage

The stage is fixed, and only serves to hold the object to be observed. There is no moving mechanism in the XY direction, and the object is manually moved when needed.

XY Measurement Stage

The XY measurement stage refers to the stage with a measuring mechanism in the XY horizontal direction, and it requires that the stage has relatively high accuracy. The stage not only has a flatness requirement on the surface, but also needs to ensure that in measurement the XY plane is always in a horizontal position during the movement.
For the XY measurement stage, especially when observing and measuring the observed object beyond the field of view, the stage can be moved, and reading can be carried out through an externally attached measurement device to measure accurately large sized objects.

XY Stage Measurement Method
For XY measurements, a crosshair is required within the measurement field of view for aiming and positioning.
The crosshair can be obtained by various means, generally on the eyepiece, using the preset reticle method, which is the simplest method.
When using the monitor screen for measurement, a cross reticle can also be used, which is placed in the photographic eyepiece optical system. This method is simple and practical, the reticle is relatively clear, and various patterns of reticle can be used. It is also convenient to adjust the alignment angle of the reticle in the eyepiece.
At present, more and more measurements use the crosshair function in the camera. The crosshairs are displayed by splicing the pixels of the same color, and even the color can be selected so that it is clearly distinguished from the background pattern, making the crosshairs more conspicuous and easy to operate. Some cameras have crosshairs that can also add multiple sets of lines, and can move horizontally and vertically so as to combine a variety of rectangular patterns of different sizes. One can apply and mark the position and size of the observed specimens. In industrial processing, it has the profilometer and projector functions.
In addition to the camera to obtain the crosshair, there is also method of using a crosshair generator, display and other devices to obtain crosshair.

During measurement, first place the object to be measured on the center position of the field of view of the stage, adjust the clear image, open the crosshair, and then move the object to be measured to the starting position to be measured, so that the center intersection of the crosshair is aligned with the said position, turn on the scale 0 position (or note the reading position), then move the object to be measured in the X or Y direction until the end point of the measurement position, then stops, and finally read through the measuring scale.

Measurement error in XY horizontal direction
During measurement, aim at the starting point of the object to be measured through the eyepiece or the cross positioning on the display, then move the stage, so that the stage is moved to the end point in the horizontal axial movement. At this time, it is necessary to ensure that the distance between the two points is the actual distance of the horizontal direction. If the stage is tilted, an angle is created between the horizontal direction and the tilted or oblique direction. The numerical value we read is actually the length of a diagonal line, thereby causing error.

For XY stage measurement, it is necessary to use a high-magnification objective as much as possible.
The objective lens has a certain depth of field. The smaller the objective lens is, the larger the depth of field will be. The large depth of field cannot reflect the image blurring conditions caused by the up and down misalignment when the stage moves horizontally: the bigger the objective magnification, the smaller the depth of field. When the stage is not flat and moves out of the depth of field range, the image will be out of focus and becomes blurred, indicating that the stage is in a non-horizontal position, and the accuracy of the measurement at this time will be higher.
In principle, the depth of field range of the objective of the microscope is the minimum error range of the flatness of the platform stage.

For XY horizontal measurement, when measuring objects with shorter lengths, this error is very small, even negligible. If the measured object is relatively long, the bigger the angle at which the stage is tilted, the greater the differential value between the oblique line of the measured image and the actual horizontal line segment of the object, and also the bigger the accumulated error will be.
Because big stage has a bigger accumulated error, when measuring a relatively bigger length, it is necessary to calibrate the error within the stage system in advance. In measurement using computer software, the value of this accumulated error can be input into the measurement result for correction. Therefore, it must be ensured that the stage is always in a horizontal state in movement, which is the most basic requirement in optical measurement.

Ways to adjust the level of the XY stage:
1. Use a cross reticle in the eyepiece or display.
2. Select an objective with the largest magnification in the microscope system, and place a calibrated line ruler on the stage (a long transparent glass ruler for calibration). The marked front of the line ruler is below the ruler, near the side of the stage countertop.
3. Overlap the starting point of the line ruler with the starting position on one side of the stage; adjust the focus, ensure that the objective is aligned with the starting position image of the line scale to obtain the clearest image.
4. Move the X direction of the stage, so that the stage moves along the direction of the line ruler, and at the same time observe whether the grid image of the line ruler is clear, and record the blurred position of the image until the end position. After completion, do the side of the Y direction.
5. Among the above results, the unclear position is the position where the stage is not flat.

If the stage is unable to maintain horizontal, after the initial position is focus adjusted to get a clear image, the image will become more and more blurred, and in most cases, the stage is tilted to one side (up or down). To solve this problem, adjust the height of the four feet of the stage, or adjust the height position of the screws at the four corners of the bottom glazing of the stage center to keep the stage horizontal.
In general, adjusting the stage horizontal can adjust the height of the position of the anchor screw of the stage, or use a very thin shim (Shim) to adjust.
Sometimes, it is also necessary to adjust the perpendicularity of the optical axis of the microscope. Use the screw that fixes the microscope to top move the microscope, to make it shift in the vertical direction, keeping the microscope in a vertical position.

Using a line ruler can also calibrate whether the distance traveled by the line ruler at each grid value for measurement is consistent with the distance read by the stage drive (for example, the reading from the micrometer or the digital display), thereby calibrating the error of the stage movement accuracy. Such errors are often caused by the empty return of the stage drive or the insufficient of stage stiffness etc.
If line ruler is not used and the stage surface is observed directly, the above results can also be obtained. Also, when the stage surface is moved to each position, that whether the surface of the stage is uneven when processing can be displayed through clear or blurred image position, and can also observe whether the flatness of the stage plane itself is within the allowable range of the depth of field of the objective.

XYZ Measurement Stage

The XYZ measurement stage has stage for measuring mechanisms in three directions, namely, the XY horizontal direction and the Z vertical direction. Generally, there is a relatively high accuracy in the XY direction, the accuracy of the Z axis is usually different from the XY direction in structure, and the accuracy requirements may also be different.

In most of the structures of the XYZ stage, the manufacturing method and accuracy of the Z direction and the XY direction are the same. However, there are also measuring devices that use microscope focusing mechanism in the Z-axis direction to generate displacement by adjusting the distance between the stage or the microscope, and to measure the displacement distance in the displacement.
The Z-axis measurement is consistent or similar to the measurement method in the XY horizontal direction, but differs in principle and measurement of error. In addition to the different accuracy errors caused by the possible differences in the XYZ mechanical structure, the error from the optical principle is more obvious.
The Z-axis measurement has relatively more limiting factors, for example, some objects being measured lack obvious focus feature points, and cannot be measured. However, in some objects that cannot be placed in the XY horizontal direction, for example, the height of the soldered electronic components on the electronic circuit board, the depth of some tube holes, they are still a better method.

Measurement method in the Z-axis direction
1. When making the Z-axis measurement, first use the intersection of the crosshairs to align the horizontal position of one measured starting point of the object to be measured, so that the microscope is focused to a clear image position.
2. Turn on the measurement scale 0 position, then find the plane position of the end point of the measured object, adjust the XY axis, move the intersection position of the crosshair to the said position, and focus up or down to find the clearest image position. In the above, it is also possible to determine the position of the starting point through the clear image of the measured starting point without adjusting the center point.
3. After reading the displacement before and after, the number of displacements occurring on the scale will be the height between the two points being measured.

Measurement error in the Z-axis direction
In the Z-axial direction, since absolute verticality cannot be guaranteed, when relative movement with the stage occurs, an angle of more than or less than 90 degrees will be generated with the stage in the tilted or oblique direction, and the more inclined the Z-axis direction, or the longer the movement, the greater the error.

If the measurement error in the XY direction depends on the depth of field of the objective and the accumulated error value of the length of the object to be measured, then for the measurement error in the Z-axis direction, in addition to the vertical error in the Z-axis direction due to the Z-axis measurement, the measurement error value in the depth of field of the objective will be much bigger. In the Z-axis measurement, after focus of measurement, the positions of the start point and the end point may actually both result in error through the twice focusing of the depth of field, and the maximum range of the error can be twice of that of the depth of field.

Because of the depth of field factor, if the object being measured cannot find the position of two different but clear focus points, it cannot be measured either. Moreover, it is also not possible to measure between two feature points smaller than the distance of the depth of field of the objective on the Z axis.

Tilt Stage

The tilt stage is centered on the Z axis of the microscope optical axis, and the XY horizontal direction is used as the baseline. Tilt stage can be used for tilting motion in the front, back, left and right directions to observe the image features of different angles of some objects.

Temperature Control Stage

Temperature control stage can perform temperature control towards the microscope stage to ensure the temperature of some observed objects, for example, the observed living body, the melting point of the observed substance after heating etc.

Mechanical Stage

Mechanical stage is a mechanical device mounted on the microscope stage for fixing and moving the slide.

Rotary Stage

The rotary stage can be rotated on the horizontal direction around the Z axis of the optical axis of the microscope as its center, and can also change the viewing angle and direction of the object to be observed.
Some rotary stage are marked with a 360-degree circumferential scale that can be used to measure angles. If there is no scale on the stage, a reticle can also be mounted on the microscope eyepiece, or an angle plate on the lens tube to measure the angle.

Before the rotating stage is used, the co-axis (having a common axis) of the rotating center and the main optical axis of the microscope needs to be adjusted. In works of area measurement, polarization and phase difference observation, especially when the rotating stage with 360 degree scale reading is used, it is all the more necessary to align the center point with the position of the optical axis. To adjust the co-axis, it is usually by using a centering eyepiece with a crosshair in the center, place a specimen with obvious featured points of details on the center position of the rotating stage, while rotating the stage, adjust the position of the stage center screw such that the center position of the specimen is always maintained at the center of the field of view of the stage.

Method of rotating stage to measure the angle:
1. First, put the object to be measured at the center of the stage, then adjust the focal length of the objective to get a clear image.
2. Take an eyepiece with a cross reticle, select an X or Y axis from the crosshair in the cross reticle eyepiece, align the starting point of the angle of the object to be measured, and record the position number of the scale on the stage.
3. Rotate the stage or the reticle eyepiece, then align the other edge of the object to the same axis of the cross reticle (the same axis as the X or Y axis just selected), and record the scale number.
4. The difference between the two angle values will be the angle value of the measured object. Repeat the above measurements several times to get a more accurate value.

Stage Specimen Holder

Stage specimen holder, also known as the specimen holder or slide holder, is a device mounted on the microscope stage for fixing the slide.

Stage Clip

Stage clip is a spring piece mounted on the microscope stage for fixing the slide or the object to be observed.

Water Droplet Plate

Water droplet plate is a device that carries the specimen of the object. Water droplet plate is generally made of metal, and has a shape of a drop of water. When the object moves, the change in the size of the field of view can be seen.

Multifunctional Slit Plate

Multifunctional slit plate is a device that carries the specimen of the object. Multifunctional slit plate is generally made of metal, and has various shapes according to different requirements, which is convenient for observing different requirements of the object.

Digital Micrometer Head

Micrometer head can be divided into mechanical micrometer and electronic micrometer. Electronic micrometer head is the micrometer head that displays the measurement results by numbers. When used in the platform, micrometer head has two functions, which can be used as a drive unit of the platform to displace the platform, and measure and read in the displacement.

Digital micrometer head operation is more intuitive and convenient than traditional mechanical micrometer head, and has many auxiliary functions.
1. The readings are intuitive and accurate, avoiding errors that may be caused by inconvenient readings.
2. It is possible to set the relative 0 position at any position, so that the starting and ending points for measurement can be set freely to improve the efficiency.
3. Free switching between the metric and the British metric system.
4. The digital micrometer head can be equipped with a digital output adapter so that the measurement result can be directly input to a computer or a DRO (Digital ReadOut) to read and store data.

Mechanical Micrometer Head

The micrometer head can be divided into two types: mechanical micrometer, and electronic micrometer. Mechanical type is a micrometer head that measures the length of displacement through the thread principle. When used in platform, micrometer head has two functions, one is to generate displacement as the drive platform, and the other is to measure the reading in the displacement.

The mechanical micrometer head is a micrometer adjustment device that measures the length using the thread principle and has a measurement resolution of up to the micron level with an accuracy of 0.01 mm.. Mechanical micrometer head is also called micrometer head, spiral micrometer, micrometer.
In experiment, micrometer head is a tool used to generate displacement and indicate the amount of the displacement. The mounting sleeve of the micrometer head is to facilitate fixed mounting on the stand base. The main ruler on the axial sleeve has two rows of scale lines: the row that is marked with number is the whole millimeter line (1mm/grid); the other row is the half mm line (0.5mm/grid); the circumferential surface of the front part of the micrometer tube is engraved with 50 equal mark lines (0.01 mm/gird).
When the micrometer tube or the fine focus knob is rotated by hand, the measuring rod advances or retreats along the direction of the axis. For every 1 gird rotated by the micrometer tube, the measuring rod moves a small displacement of 0.01 mm along the axial direction, which is also called the graduation value of the micrometer head. The micrometer head reading method is to read the scale value exposed on the main ruler of the sleeve first, pay attention to the half-millimeter line; then read the numerical value on the micrometer tube aligned with the horizontal line of the main ruler, and 1/10 graduation can be estimated.

Stage Extension Adapter

Adjust the adapter of the stage position in order to align the stage and the microscope observation center.

PCB Holder

PCB holder is a support base used to support the circuit board to maintain horizontal. There are components under some circuit boards, or when one doesn’t want to come into direct contact with the underlying base, use this holder to support the circuit board for microscopic inspection and operation.

Electrical Control

Electric/CNC platform refers to the movement mode operated and controlled by motor or digital signal during the XY or Z-axis focusing of the microscope and the movement of the platform.

Coaxial Reflection Illuminator

Coaxial reflection light is realized by a coaxial reflection illuminator. Coaxial reflection illuminator is placed horizontally, parallel to the worktable, and is at a 90 degree angle to the optical axis of the microscope. When the illumination light passes through the coaxial reflection illuminator, the light is first turned through a reflection prism or beam splitter to a 90-degree angle, and is vertically (or nearly vertical) irradiated onto the surface of the object to be observed, and then reflected back to enter into the eyepiece through the objective lens.
The coaxial reflected light is suitable for illuminating planar objects and objects with high reflectivity. In addition, when the opaque or translucent objects are observed by large magnification objective lens, if the working distance is too short and an external light source cannot be used, the coaxial reflected light may be the best and the only choice.

Coaxial reflection illuminator, usually consisting of illumination light source, lamp chamber, condenser lens, aperture diaphragm and field diaphragm, color filter converter, and heat sink etc., achieves light emission and control.

The light or lamp chamber is generally made of a metal shell, with a ventilating vent or heat sink on the outside, but does not leak light, and has a spiral or top wire mechanism for adjusting the light axis.

Light source filament position and coaxial adjustment of the center of the optical axis
Because the illumination source is modularized with the microscope body and also, when in use, due to movement operation etc., the position of the filament of the illumination source and the illumination optical axis often deviate, which causes the Kohler illumination system to be damaged, thereby affecting the brightness of the field of view and the uniformity of illumination.
The main reason that affects the uniformity of illumination is that the position of the filament of the light source is not on the optical axis, which makes the field of view appear uneven. The main reason that affects the brightness of the field of view is that, after passing through the condenser for condensation, the illumination light is not focused on the aperture diaphragm plane.
The above therefore needs to adjust the position of the bulb in the coaxial reflection illuminator. Firstly, by adjusting the positioning screw on the light source, change the position of the lamp holder, and adjust the illumination bulb up and down, left and right, so that the filament is located on the optical axis of the center. Then, loosen the fixing screws on the condenser, move the condenser back and forth, so that the illumination light will converge at the center of the aperture diaphragm, and then tighten the screws. This not only makes the illumination in the field of view the brightest, but also uniform, and has no filament image.
Some metallurgical microscopes are equipped with "light chamber adjustment objective lens". When using, first remove an objective lens, rotate the light chamber adjustment objective lens into the nosepiece, and transfer it into the imaging light path, and replace the objective lens for the above adjustment.

Transmitted Illuminator

Transmitted illuminator is a kind of illumination observation method in which an object to be observed is placed between an objective lens and the illuminator or light source, it is suitable for transparent or translucent object to be inspected, and the vast majority of biological microscopes belong to such illumination methods. When applied on a stereo microscope, it can also be used as a kind of bright background to show the contour of the object being observed, showing the accurate edges when measuring.

Transmissive lighting can also be divided into two types: "central illumination" and "oblique illumination":
Center illumination: this is the most commonly used transmissive illumination method. It is characterized by the central axis of the illumination beam being in the same line with the optical axis of the microscope. It is further divided into "critical illumination" and "Kohler illumination".
Oblique illumination: for this kind of illumination, the central axis of its illumination beam is not in the same line with the optical axis of the microscope, but forms a certain angle to the optical axis, illuminating obliquely on the object, and therefore it is called oblique illumination. Stereo microscope often uses oblique illumination for easy observation of objects of different heights, and increase the stereoscopic effect of images.

Mirror

Usually, a plane mirror or a concave mirror is used under the stage to reflect external light source illumination. This kind of concave mirror is generally used in low magnification objective lens without a condenser.
Some reflection mirrors can use natural light directly for reflection in microscope illumination without the need to use a power source and a light bulb for lighting.
When high-intensity glare illumination is required, but also continuous-band incandescent or halogen lamps must be used, the use of a mirror or reflector can effectively eliminate the uneven illumination of the image by the filament of the incandescent lamp or the halogen lamp.

Diffuser

Diffuser is usually white or milky white glass plate in appearance that can produce a diffusing effect inside, or use other materials such as plexiglass, it can make the lighting more soft and even.

Phase Contrast Kit

Phase contrast kit mainly includes annular diaphragm, phase contrast objective with a phase plate, and a phase telescope for central alignment.
The annular diaphragm is placed near the aperture diaphragm, and there are single pieces, some are combined into a diaphragm group. There are also some that make the annular diaphragm into a turntable and combine together with the condenser. The annular diaphragm is to use a glass, coated with metal film, to block the light. When the light passes through the narrow slit of the diaphragm, it forms a hollow light cone, and different diaphragms are used corresponding to different objective lenses so as to generate diffraction and interference effects.

The phase plate is mounted on the back image focal point of the objective lens. It is to use a piece of glass, coated with a light absorbing material (magnesium fluoride or other electrolyte) and a layer of metal film at the ring that is transparent to the corresponding annular diaphragm, so that the phase of direct or diffracted light passing through the phased annular diaphragm can be delayed by 1/4λ. The phase plate absorbs part of the light, extends the optical path and delays the phase of part of the light. After the two beams of light are combined, the interference is strengthened, and the vibration amplitude is increased or decreased, resulting in a phase difference, which makes various structural features more clear.
Phase plates are usually used in two forms:
Negative contrast: delay the direct light by 1/4λ. After the two sets of light waves are combined, the light waves are added, the vibration amplitude is increased, and the specimen structure becomes much brighter than the surrounding medium, forming a bright contrast.
Positive contrast: delay the diffracted light by 1/4λ. After the two sets of light are combined, the light waves are subtracted, the vibration amplitude is reduced, and the specimen structure becomes much darker than the surrounding medium, forming a dark contrast.

Annular diaphragm and phase plate adjustment
Phase telescope works on the coaxial correction of the annular diaphragm and the phase plate. When using a phase-aligned telescope, it temporarily replaces one eyepiece, adjust and focus the image of the object on the phase plate, and then observe and adjust the auxiliary lens of the condenser. Adjust the annular diaphragm and the right corresponding to the phase plate to its concentric position, so that the beam of the annular diaphragm and the phase ring of the phase plate are the same size, and the annular beam is completely projected on the phase ring.

Some microscopes have a Berrand lens that can be switched in the optical path, which is to correct the position of the annular diaphragm and phase plate. When using, screw the Bertrand lens into the optical path, adjust the focus and see the images of the annular diaphragm and the phase plate, after adjusting its position, rotate the Bertrand lens out of the optical path.

EPI-Fluorescence Kit

EPI-fluorescence kit, also known as the incidence fluorescence kit or reflection fluorescence kit.
It is an accessory device that excites and emits fluorescence for fluorescent microscope illumination, forming an illumination system that consists an illumination source that can emit ultraviolet light, a configured fluorescent condenser, and filters for excitation and emission of fluorescence etc.

Fluorescence microscope requires a complete set of filters. The fluorescence excitation block is the core component used to excite fluorescent specimens and observe fluorescence in a fluorescence microscope. The excitation and emission filters, after combination, are placed in a filter cube. When the user replaces the filter, it is relatively convenient. The component consisting of several filter blocks in the excitation module includes:
Exciter filter: selects the light that passes through a certain wave band to excite the specimen to produce fluorescence.
Dichroic mirror (commonly known as a mirror): set at a 45-degree angle in the cube, reflect the excitation light downwards and transmit the fluorescent upwards.
Barrier filter: transmit the emitted light, that is, fluorescence, and at the same time block the reflected light in the various stray light and excitation light.

Fluorescence is excited by light of a specific wavelength, and the emitted light that is excited has also a specific wavelength. Therefore, it is necessary to select suitable excitation blocks (mainly selecting the light wavelength parameters of excitation light filter, dichroic mirror and barrier filter).

The excitation module is generally named after the basic color tone. The first letter represents the excitation spectrum region of the wavelength, that is, the color tone. For example, UV represents ultraviolet light, V represents violet, B represents blue, and G represents green. The subsequent letter represents the glass, and the numbers represent the model features. For example, BG12 is a kind of blue glass, B is the first letter of blue, and G is the first letter of glass.

UV-Filter of Fluorescent Microscope

UV-filter of fluorescent microscope is installed under the eyepiece of a fluorescent microscope, filtering and blocking the ultraviolet to avoid harming the observer's eyes.

Ring Light

Ring light is a kind of "shadowless lamp", which is illuminated from a 360-degree annular angle, and can observe the change of the edge and height of the object to be observed. It is very suitable for surface illumination of non-reflective objects, and is often used to observe and detect the edge of objects, surface structure, traces, etc. such as components on the printed circuit board, liquid crystal glass substrates, metal and non-metal surface dust, scratch damage, various kinds of particles, etc., and is also the most common way of illumination for stereo microscopes.

Circular fluorescent light bulb is a bulb of peripheral illumination with no direction, it requires a reflective bowl to converge the light beam onto the illuminated object below the microscope. The diameter of the tube and the design of the reflective bowl determine the distance and position of the beam convergence point. The LED ring light consists of different LED bulbs. By setting the angle of the bulb, all the illumination beams are concentrated at one focus, and the annular or loop fiber is mostly designed by the incident angle of the fiber exit port.

The central concentration range of the ring lamp usually needs to coincide with the focal length of the objective lens of the stereo microscope. The working distance of the 1X objective lens of stereo microscope is generally about 80-100mm, which is the focus convergence position of most of the ring lamps. Because the external light source itself has a certain height, therefore the concentration center range of the ring light source is generally between 45-65mm. If below 45mm, shadow starts to appear in the middle; if higher than 65mm, the light in the middle will gradually diverge, and the brightness will decrease. When a small objective lens (such as 0.75X/0.5X) is selected, the lighting effect can basically be achieved; but when an objective lens with larger magnification is used and the working distance is relatively small (for example, 2X), the illumination center of the ring lamp will be a "black center", the effect of lighting will be relatively poor.

Ring lights are usually stuck at the bottom of the nosepiece. Tighten the screws. In general, the electrical wires should be pulled to the back of the operating position, the switch or button should be placed on the side for easy operation.
Generally, the ring light needs to be stuck with a lens frame at the bottom of the nosepiece. On the objective frame, there is a card slot for screw fastening. There are also microscope nosepieces that contains a card slot position of its own, and does not need an objective frame.

Rectangle Light

Rectangle light is generally used as a backlight. Its light-emitting area is rectangular, and lighting can make a sharp contrast between objects and background, especially suitable for testing of transparent and translucent objects.
There are generally two types of illumination methods for backlight sources, one is direct Light and the other is refraction light. Direct light is usually to base the illumnant light source (light bulb) directly on the illuminating surface, and then illuminates through the light transmissive plate (usually frosted glass or plexiglass) on the backlight source. The advantage is that the intensity of the light is relatively high, and disadvantage is that it is sometimes uneven. The refraction light is that the illuminant light source is on one side of the backlight plane, and then refracts/diffuses inside to emit light on the light transmissive plate, the advantage is that the uniformity of light is better.
When backlight source is used as backlight, it is mostly used under the stage with a rectangular window, and is stuck with a screw. Backlight source can also be placed separately.

Round Light

Round light source, typically functions as a background light or backlight, is used when observing transparent or translucent objects.
Round light source is direct light, and generally, its light bulbs are made on the flat backplane of the light source.
The brightness of backlight needs to be adjusted according to the condition of the object to be observed. If the object to be observed fills all the fields of view of the microscope for observation, the backlight can be brighter. If the object to be observed is very small, and has not filled all the field of view of the microscope for observation, the backlight should be slightly darker, otherwise the field of view will be too bright to see the object.
As a separate backlight or bottom light, it can usually be mounted to the microscope plate position. When it is temporarily used, it can be placed directly on the base, and the object to be observed is directly placed on the light source, and removed when not in use.

Line Light

Line light source, also called "linear light source", refers to a point-like source of light that can emit continuous visible light. Light travels linearly in one direction in space, and the cross-sectional width is a "linear" source of light.
In microscopic illumination, linear light source can easily control the angle of the illumination beam. It is mainly used for observing and scanning objects with observation surface reflection, which can effectively reflect the features such as unevenness, dust and scratches on the surface of the planar object.
In machine vision, line light source is often used in conjunction with a line array scanning camera.

Diffuse Light

Diffuse reflection is a phenomenon in which light projected on a rough surface or an irregular medium is reflected in all directions of space.
When a parallel incident light hits a rough surface, the surface reflects the light in all directions, and therefore, even though the incident rays are parallel to each other, but because of the inconsistency of the normal directions of the various points, the reflected rays are irregularly reflected in different directions. This reflection is called "diffuse reflection" or "diffuse", but the frequency of the starting light does not change.
In microscope illumination, diffuse light can provide highly uniform, flat, shadowless light. For objects with high reflectivity, such as spherical bodies, multi-faceted crystals, sharp and reflective objects, specular reflection objects, etc., diffuse light can eliminate reflections from objects and improve image quality.
The disadvantage of diffuse light is that they are relatively large in size, and must be larger than the object being observed. The position of the illumination is relatively low, occupying a larger working space, sacrificing the working distance between the microscope and the object to be observed, which causes inconvenience to the operation under the microscope. However, for conventional inspection observation and measurement works, it is not affected.

Spot Light

Spot light source of microscopic illumination, usually refers to the “spot” or dot shaped light source, converged at the light exits after the power source emits light. It is usually used for “oblique illumination”, and can be angled with the optical axis of the microscope, very suitable for illumination detecting the cracks, pipe walls etc. of some objects with “height and depth”. When focusing is required, a lens can be added in front of the spot light source for light concentration, making the illumination more uniform.
The focal length of the spot light source usually falls directly on the focal plane of the lens/surface of the reflector in order to achieve maximum brightness and illumination effect.

In spot light source, there is a kind of dual point light. In optical fiber illumination, it is called double pipe light guide, which can adjust the angle and brightness freely, so as to adjust the light and shadow of the illumination to reach the optimal position.

There are also spot light source, which are split into multiple points of illumination on a ring to become a multi-point illumination source, it is a compromise between ring illumination and spot illumination.

Color Filter

Color filter is a type of filter that allows light of only a certain wavelength and color range to pass, while light of other wavelengths is intercepted. Color filter is made of colored glass, and it has various bandwidths and color for selection.
Both artificial light source (lamp light) and natural light (daylight) are all full-color light, including seven colors, namely, red, orange, yellow, green, blue, indigo and purple. As the microscope illumination, different types of light sources have different color temperatures and brightness. In order to adjust the color of the light source, it is necessary to install a filtering device at the light exit port of the light source, so that the spectrum of a certain wavelength band is transmitted or blocked. Color filter generally can only be added to the illumination path to change the color of the illumination source and improve the contrast of the image, but generally it is not installed in the imaging path system, which affect the image quality.

There are many types of color filters. In addition to the color requirements, color filters of different colors also contribute to the imaging quality. Color filters using the same color will brighten the color of the image.

Of the traditional daylight filter, there are relatively more red and yellow light in the lamp light, the resolution is not high, and the observation is not comfortable. The use of daylight filter can absorb the color between yellow to red spectrum emitted by the light source, thus the color temperature becomes much closer to daylight, making microscope observation more comfortable, and it is one of the most used microscope color filters.
Daylight blue filter can get close to the daylight spectrum, obtain more short-wave illumination, and improve the resolution of the objective lens. For example, using blue color filter (λ=0.44 microns) can improve the resolution by 25% than green color filter (λ=0.55 microns). Therefore, blue color filter can improve the resolution, and improve the image effect observed under the microscope. However, the human eye is sensitive to green light with a wavelength of about 0.55 microns. When using blue color filters for photomicrography, it is often not easy to focus on the projection screen.
Yellow and green filters: both yellow and green filters can increase the contrast (i.e. contrast ratio) of details of the specimen. As far as the achromatic objective lens is concerned, the aberrations in the yellow and green bands are better corrected. Therefore, when yellow and green color filters are used, only yellow and green light passes, and the aberration will be reduced, thereby improving the imaging quality. For semi-apochromatic and apochromat objectives, the focus of visible light is concentrated. In principle, any color filter can be used, but if yellow and green filters are used, the color will make the human eye feel comfortable and soft.
Red filter. Red has the longest wavelength and the lowest resolution in visible light. However, red light image can filter and eliminate the variegated background in the image. Therefore, so it has a very good effect for some applications that do not require color features for identification, and the edges and contours of the image are also the clearest, which is more accurate for measurement.
Medium gray filters, also known as neural density filters, or ND for short, can uniformly reduce visible light. It is suitable for photomicrography and connection to computer monitors for observation. ND can be used for exposure control and good light absorption, and reduce the light intensity while not changing the color temperature of the microscope light source.

Fiber Optic Light Source

Fiber optic light source refers to an illuminating light source that does not contain or contains less spectrum of infrared heat radiation in a illuminating or light guiding body, for example, the popular LED light source, which is a typical illuminator fiber optic light source. In microscopic illumination, the optical fiber cold light source (commonly referred to as “cool light”) means that, after the illumination beam is transmitted through the optical fiber of the light guide body, the heat radiation is not brought to the light exit port, thereby achieving "cold light" effect.

The portion of the illuminating light source of the optical fiber has been conventionally illuminated with a halogen light source. In recent years, high-power LED lighting has been widely used. Although the bulb of halogen light source can generate a lot of heat radiation, because of its high brightness when emitting light, it belongs to full-band light, with good color reproduction and comfortable observation by human eye, and therefore is still irreplaceable in some applications.
Luminous light sources usually require a high-power light source to achieve strong light, therefore heat dissipation is very important. Whether it is a halogen light source or an LED light source, fan cooling is usually adopted.

Fiber optic lighting application has many advantages:
1. The thermal conductivity of the optical fiber is poor. When the light source (light bulb) emits light, the thermal radiation, after being separated by the optical fiber, is not transmitted to the object to be observed. So, while maintaining the wavelength and brightness of the light, it becomes "cold light". When using strong light, cold light may not damage the observed objects, especially in medical and biological applications.
2. Single light source can be transmitted through the optical fiber, and at the same time there are multiple light-emitting points with the same light-emitting characteristics. The light-emitting port can be arranged at different positions and angles, or made into different shapes, such as double-branch lighting, ring lighting, multi-point lighting etc.
3. The light source host and the light exit port illumination point are transmitted through the optical fiber, and therefore the host can be placed in a safe or suitable position without affecting the illumination position of the light exit port, so that there will be more flexibility in design and use.
4. The light exiting port illumination point is transmitted through the optical fiber, and it can filter freely the wavelength of the light at the light source position in the front end of the light entrance, increase the polarization effect, and adjust the brightness and darkness. For example, improve the contrast and contrast ratio of the details of the object to be observed through various color filters, filter out the ultraviolet and infrared light, and reduce damage to certain items..
5. In the light source host and optical fiber used in fiber optic lighting, the service life of the optical fiber can be decades, and the design separating the light source from the optical fiber makes the light source easy to repair and replace.

Optical Fiber Light Guide

Optical fiber bundle for illumination, is referred to as optical fiber light guide for short.
Optical fiber light guide is a fiber core made of transparent material (typically, glass fiber is made of silicon dioxide). Around the fiber core, a cladding layer is formed, using a material having a refractive index lower than that of the fiber core, that is, if the refractive index of the fiber core and the cladding layer are n1 and n2, then n1 must be >n2. The transmission of the optical fiber makes use of the principle of total reflection of light. In this fiber core medium, light is to maintain its characteristics of optical waveform for transmission, wherein the fiber core portion of high refractive index is the main channel for light transmission, while the outer casing of low refractive index covers the entire fiber core. Since the core has a higher refractive index than the outer casing, total reflection occurs, and therefore light can be transmitted in the fiber core.

The core of the optical fiber is generally classified into glass fiber, quartz fiber, plastic fiber, and liquid core fiber etc.
Microscope illumination usually uses glass fiber, which can have better transmittance for light of different wavelengths. For glass fiber, its optical core material is multi-component optical glass with high refractive index, whereas its cladding material is optical glass with low refractive index. The commonly used multi-component glass formula include: sodium-borosilicate glass (Na-B-Si), potassium-borosilicate glass (K-B-Si), sodium-zinc aluminoborosilicate glass (Na-Zn-Al-B-Si), and the like.
Glass fiber, made of optical glass, has a much higher transparency than a ordinary set of glass, but still has a relatively high attenuation value, generally about 1dB/m.
The lighting fiber optic wire is very thin, and cannot be bent at a large angle. Generally, its minimum bending radius ≥30D (Min. bending radius ≥30D). Check the breaking of the fiber optic wire, you can use one side section to face the light, and the other side section to see the dark part. If there is too much break, it can’t be repaired, but the entire fiber be replaced.

Coupler/C-mount Adapter

Coupler/C-mount adapter is an adapter commonly used for connection between the C-adapter camera (industrial camera) and a microscope.

Digital Camera Adapter

Digital camera adapter is the adapter that connects the digital camera to a microscope, including various card machines. Because the standard adapters of digital camera lenses of different manufacturers in the past are different, the design and use of this application is more complicated, it is therefore necessary to design adapters for most of the different manufacturers. At present, its current application is becoming less and less.

DSLR Camera Adapter

The lens adapter of DSLR cameras of different manufacturers uses different F-MOUNT adapters (also called extension ring or external metering), and then connects to the DSLR camera lens and microscope.

Immersion Tray

Gem immersion oil observation is called oil treatment. Oil treatment is to clamp the gemstone with a gemstone clip, put it into an oil immersion tray, and observe it with a gem microscope.
The engraving plane of polyhedral gemstone can increase the refraction and reflection effect of light, affecting the gemstone observation and producing reflective interference. Placing the gemstone into the oil immersion can minimize the refraction and reflection interference of light, highlight the inclusions and images that differ from the gemstone's refractive index, and observe more clearer details of the image. Moreover, the fissure plane of the gemstone can also show the halo resulting from the interference effect because of the oil.
Usually, immersion oil is to use a liquid that has a similar refractive index of gemstones, such as water (refractive index 1.33), benzene (refractive index 1.56), and the like.

Mobile Phone Adapter

Mobile phone adapter is an adapter that connects the mobile phone to a microscope to take a microscopic image with the mobile phone.

At present, there are many kinds of mobile phone adapters popular in the market, most of which do not have a lens, and they form image directly by using the microscope eyepiece. Many of these products have eyepiece fixing problems. The biggest problem is still the field of view of the image. Generally, the mobile phone lenses are mostly a wide-angle lens with an angle of more than 80 degrees, and the maximum is close to 100 degrees. The angle of view of the eyepiece of the microscope is relatively small. The angle of view of the eyepiece is generally about 30°, and the angle of view of the wide-angle eyepiece is above 50°. Therefore, the imaging range on the screen of the mobile phone is relatively small, forming the "black border" and "dark angle" phenomenon.
Using the Zoom function of the mobile phone, the dark corners can be removed by magnifying the image. But in fact, the effective pixels of the mobile phone are sacrificed, and generally, only 1/3~1/2 of the pixel of the mobile phone is used.
Adapter presetting camera lens uses coupler/C-mount adapter with a large field of view, which can help with the above-mentioned field of view and fixation problems, but may not be suitable for all mobile phones, or the imaging range may be different.

Analog Camera

What the camera captures and outputs are analog signals.

USB Digital Camera

What the camera outputs are digital signals, which are output to the computer via the USB adapter.
There are two kinds of popular USB adapters popular on the market, namely USB2.0 and USB3.0. Both kinds of adapters need different data lines to work.

Camera Conversion Adapter

For the model of microscopes of some manufacturers, when installing the camera and industrial camera, a convertible adapter is required to be installed on the trinocular head of the microscope.

GigE Camera

The camera outputs digital signals, which are output to the network via a gigabit network.

1394 Firewire Camera

The camera outputs digital signals, which are output to the computer via the 1394 adapter. There are usually two types of adapters, namely, a and b.

VGA Digital Camera

The camera outputs digital signal, which are output to the display via the VGA adapter.

HDMI Camera

The camera outputs digital signals, which are output to the display through the HDMI adapter. There are usually two types of HDMI adapters, namely, HDMI A type adapter, and HDMI Mini type adapter.

LCD Display Digital Camera

LCD display digital camera is a combination of a digital camera and a display.

Tablet PC Camera

Tablet PC camera is a combination device of a digital camera and a PC computer with a system.

Measurement Software

Measurement software is a software that collects, stores, compiles, and measures the image by the computer's image processing software after the camera captures the said image. Generally, measurement software is used along with the camera hardware.

Reticle

Reticle is generally also referred to as eyepiece reticle, or reticule, graticule, cross hair.
Reticle is an optical component with a certain mark placed inside the eyepiece. Based on different applications, reticle can be used for measurement, calibration or aiming.
Reticle is mainly used for the measurement of length, angle or area of the object to be measured under the microscope. The reticle measurement is a "non-contact measurement", that is, the measurement value is obtained by measuring the optical image without touching the object to be measured, which is very suitable for some small specimens, organisms, and irregular objects.

Eyepiece reticle has patterns of various shapes and sizes. Common types of eyepiece reticle are: straight, cross, mesh, circle, angle or combination shape. Between each grid it is also equidistant. However, for eyepiece reticle, one cannot read directly the number under the microscope, but convert firstly the multiple after magnification of the microscope objective lens. In short, after the object is being magnified by the objective lens, the real image of the object reaches the focal length of the eyepiece (10 mm below the fixed surface of the eyepiece), which is exactly the position of the eyepiece reticle, and what the eyepiece reticle reads is actually the image of the object after being magnified by the objective lens. Therefore, for the actual numerical value, the actual size of the image should be divided by the magnification of the objective lens.

In addition, for eyepiece reticle measurement, it can also be calibrated first by the objective micrometer before measurement. The method is: first, place an objective micrometer on the stage, after the focus is clear, record the magnification number of the objective. Then, the eyepiece reticle is overlapped with the scale pattern of the objective micrometer, so that the 0 points of the two are aligned, a scale value with a completely coincident scale is found backward, the grid values of the reticle eyepiece and the objective micrometer are respectively read and converted, and then the calibration value is used as the actual measurement value of the eyepiece reticle.
This method is relatively more complicated. First, it is necessary to constantly convert the reading value and the calibration value of the eyepiece. Secondly, each time when the objective lens with different magnifications for observation is changed, it needs to be re-calibrated. This is only suitable for use in strongly repetitive microscope observations and work in order to be efficient.

Reticle Installation
The reticle is installed in the eyepiece tube, and some eyepieces have been installed with reticle before leaving the factory. Since the requirements are different, users can also buy different reticle, and then install it on their own microscope.
To install the reticle yourself, first make sure that the eyepiece of the microscope can be self-removed from the microscope eyepiece tube (generally, for microscopes, all their eyepieces can be removed, and some need to loosen the screws fastened on the microscope eyepiece tube to remove the eyepiece.)

For eyepieces on which reticle can be installed, you should pay attention to the following features and requirements:
1. Whether the tube wall of the eyepiece has a “mounting/installation surface” on which the reticle is placed. Generally, the eyepieces are located 10mm below the lower lens. This position is the focal plane of the eyepiece. The reticle is installed in this position to be clear.
2. Whether it has "Eyepiece Reticle Fix Ring". There are generally two ways for this fix ring: one is that there is the thread on the inner wall of the eyepiece tube, a metal fix ring with a card slot for positioning when using a screwdriver, by rotating the screwdriver, the reticle is pressed on the inner wall of the eyepiece.
There is also a"plug ring type"fix ring, usually made of plastic material, which is elastic and inserted into the eyepiece tube, and then stuck on the inner wall of the eyepiece tube to press the reticle.
If this"fix ring" is missing in the eyepiece tube, please contact your service provider to describe the above situation, and some service providers can provide this fix ring.
3. The tick marks of the reticle are all on top of the reticle. Generally, all reticles of the glass material have a certain thickness, and the tick marks of the reticle is on top of the reticle to ensure that all the tick marks are in the eyepiece focal plane (10 mm below the eyepiece) when using the reticle of different thickness.
4. Measure the diameter of the inner wall of the microscope eyepiece tube, to select the appropriate size of the reticle.

Upon understanding the above, if you need to choose reticle for different purpose of use, please visit Bolioptics.com to select reticle with a different pattern for use.

Micrometer

Micrometer is also called objective lens micrometer, or stage micrometer.
Micrometer is a scale placed on the stage to compare and measure the length, width, area, size, angle and shape of the object to be observed under the microscope.

The intuitive numerical value obtained by the micrometer compared against the observed object is the actual numerical value of the object observed. Although it has been magnified by the microscope, the measured value does not need to be converted.
In addition to measuring and reading directly under the microscope, the objective micrometer can also be used as a measuring scale to calibrate the results of measurement of the microscope after magnification.
According to different needs, various kinds of scales can be etched on the objective micrometer, such as straight lines, crosses, grids, circles and angles. In general, the minimum standard value of grid can reach 0.01mm, and there are differences of metric systems.

Micrometer has bright field and dark field distinctions, and its measurement method and standards are the same. The bright field is to etch black ruler on transparent glass, suitable for measurement under bright field microscope or bright specimen. The dark field is to etch bright ruler under a dark background, to facilitate observation under a relatively darker field of view and specimens.

Target

Target, also known as test target. If it is of film material, it is usually called film ruler.
Target is an optical imaging device that is used to evaluate, identify, compare, calibrate, and measure under the microscope. Target can be used to test the optical parameters of the image analysis of the performance and quality of the imaging system, such as sharpness, depth of field, and resolution, etc., or measure the dots, lines and angels etc.
In terms of materials, target has different materials, such as glass and film etc.

Glass Slides

Glass slide is a glass piece or a quartz piece on which a biological specimen is placed when observing through the microscope. When preparing sample, the cell or tissue, after being sliced and treated, is placed on a glass slide, and the cover glass is placed thereon, and then the glass slide is used for observation under the microscope.

Glass slide requires good light transmission, and its surface flat and even. For different application requirements, different glass slides can be selected.
Glass sides are generally made of standard rectangles. The general standard size is about 75x25mm, the conventional thickness is 1mm, and there are also 2mm, 3mm, etc., and the thickest can be up to 8mm.
Generally, the surface and edge of the glass slide are treated with various forms, such as transparent, frosted, colored frosted, single concave, double concave, and edging etc.
Classified according to materials, glass slides can be divided into common float glass slides and quartz glass slides.
Classified according to cleaning requirements, glass slides can be divided into wash-free slides and non-wash-free slides. According to requirements for use, glass slides can be divided into microscope glass slide and cell culture glass slides.

Glass slides should be cleaned. Use finger and edge contact as much as possible, avoid direct finger contact with the surface of the slide so as to avoid leaving fingerprints or smudges on it. If so, after washing with water or alcohol, wipe it off with gauze or tube wiping tissue.

Cover Slips

Cover slip is a piece of glass that covers the biological specimen in a microscope specimen.
Cover slip is generally made of square and round, and its size is typically smaller than glass slides, with a standard thickness of 0.17 mm. After imaging is formed by the objective lens and upon passing the clover slip, the front length is changed, so the manufacturer usually follows the 0.17mm manufacturing standard of thickness of the cover slip. When the objective lenses of different manufacturers are interchanged, the difference of this parameter may affect the parfocality of a set of objective lenses, that is, when the nosepiece is rotated, the objective lens will be defocused, leading to the lowering of the image quality. Some professional objectives may not require the use of cover slips, or may be equipped with focal length correction rings that replaces the thickness of the cover slips, so as to accommodate applications where cover slips cannot be used.

Cover slip can flatten the solid slice sample to form the liquid sample into a flat layer of uniform thickness, so that the plane of the slice is kept equidistant from the objective lens, to avoid repeated adjustment of the focal length of the objective lens during observation.
Cover slip can seal the sliced sample, thereby delaying the dehydration and oxidation of the sliced tissue. Cover slip can keep the slice in an appropriate position so as to avoid dust and accidental touches. In microscopic observation and use, cover slip can prevent the microscope objective from touching the sample slice, or making the slice dirty or contaminating the objective lens. Especially when using an oil immersion objective lens, cover slip can prevent contact between the immersion liquid and the sample.

Prepared Slides

Slide samples are glass slides that contain various kinds of specimens and styles, usually they have label marked contents.
There are various kinds of slide samples, and the commonly seen slide samples include are cells, blood, algae, bacterial culture fluid, various tissue sections of insects, animals and plants etc.
According to the different materials and production methods of the specimens, the specimens are produced by the smear method, the tableting method, the slicing method, the loading method, etc., and sometimes dyeing treatment is required.
It must be guaranteed that the specimens are smooth, uniform, clean, and closed, not easily dehydrated, decolorized and oxidized.

Sneeze Guard

Sneeze guard is mainly to provide isolation and protection between the operator and the object being observed.
When using ultraviolet light, although the ultraviolet radiation dose is not high, long time observation can have a harmful effect on the human eye, and therefore it is necessary to use sneeze guard to isolate.
The sneeze guard can also isolate harmful, radiating, and volatile substances to ensure the safety and health of the operator. On the other hand, it can also prevent people from exhaling, sneezing, etc. during operation, thereby polluting the observed objects.

Dust Cover

Dust cover is for maintenance of microscope in the unused state. The most common dust ocver is to cover the microscope with various kinds of plastic and chemical fiber cloths to prevent the microscope from being contaminated by dust, gas and other contaminants, etc., the cost is low and simple to operate. There are also other ways, such as covers made of glass or plastic material for protection, but they are relatively heavy, with poor adaptability, and easy to be bumped.

Wire Harness

Invented in 1879 by the American inventor Thomas Alva Edison, the incandescent lamp is a kind of thermal radiation light source that electrically heats the filament to an incandescent state, using heat radiation to emit visible light.
Incandescent lamps are widely used in low-end microscopes because of their very good light color rendering and light collecting performance, continuous spectrum, simple lighting circuit, low investment of one-time cost, and ease of use.
However, the conversion efficiency of the photothermal energy of incandescent lamp is very low, only 2% ~ 4% of the electrical energy is converted into light that the eye can perceive. Its heat dissipation is not good, the bulb and the lampshade can be relatively hot, the condensing effect is poor, and change of power supply voltage and repeated switches all have an impact on the service life of the lamp. Therefore, they are gradually withdrawing from applications in most fields.
Incandescent lamps used on microscopes must use low-voltage safe voltage, typically a 6 or 12V power supply.

Optical Instrument Cleaning Supplies

Optical instruments cleaning products include: special lens cleaners, cotton swabs, lens tissue, blow balls, brushes, cleaning cloths, etc., for daily cleaning and maintenance of the instrument.
The exposed optical parts of the microscope, such as the eyepieces and objective lenses etc., should be kept clean; otherwise, it will not only affect the optical imaging quality, but also absorb the water vapor if exposed to long to cause mildew. It is necessary to clean the dust and smudges on the lens at any time with blow balls and brushes etc. For stains that are difficult to clean, special optical cleaner must be used, and scrub with the cotton swab as required.
The plating surface of the metal part must be wiped clean repeatedly with a clean cloth after cleaning with a cleaning solution so as to prevent moisture.

Cedar Oil

The cedar oil has a refractive index n=1.515, which is used for oil immersion objective to increase the refractive index of the objective medium, thereby increasing the numerical aperture of the objective lens and improving the resolution effects.

Dyeing Agent

The details of the biological specimens have little difference in refractive index, reflectivity, color, etc. With the characteristics of selective coloring of details of the biological specimens, use dyeing agents for chromogenic reaction, thereby improving observation of the characteristics of details of the specimens.
As a dyeing agent, it needs to meet two basic conditions: one is color; the other is to have affinity with the dyed tissue. Observing dyed specimens with a microscope, gentian violet solution or other alkaline dyeing agents, such as acetic acid magenta solution, is generally used for dyeing. Details of the specimens dyed with gentian violet were purple, while chromosomes dyed with acetic acid magenta were red. These two kinds of pigments are referred to as basic dyes, but their solutions were PH acidic.
For different needs and applications, there are a variety of professional dyeing agents, please query and apply as needed.

Packaging

After unpacking, carefully inspect the various random accessories and parts in the package to avoid omissions. In order to save space and ensure safety of components, some components will be placed outside the inner packaging box, so be careful of their inspection.
For special packaging, it is generally after opening the box, all packaging boxes, protective foam, plastic bags should be kept for a period of time. If there is a problem during the return period, you can return or exchange the original. After the return period (usually 10-30 days, according to the manufacturer’s Instruction of Terms of Service), these packaging boxes may be disposed of if there is no problem.

Halogen Light

The halogen lamp is filled with a halogen gas, such as iodine or bromine in the bulb. At high temperature, the sublimated tungsten wire is chemically reacted with the halogen, and the cooled tungsten is re-solidified on the tungsten wire to form a balanced cycle, avoiding premature fracture of the tungsten filament. Therefore, halogen bulbs have a longer service life than incandescent lamps. At the same time, because the filament operates at a much higher temperature, it has therefore much higher brightness, color temperature and luminous efficiency.
The halogen lamp has maintained the advantages of incandescent lamps: simple, low cost, easy adjustment and control of brightness, good color rendering (Ra=100), and its color temperature can reach up to 3000K. The disadvantage is that the bulb is relatively hot in the working state, noise is generated when the fan is used for heat dissipation, and its service life is shorter than the LED lamp.
The halogen lamp power supply voltage is usually divided into DC 12V, 21V, 24V, etc., and the service life of an ordinary bulb is about 50-200 hours.

Precautions:
Most halogen bulbs look similar, but one must check the voltage and power of the bulb used by the microscope, otherwise it may fuse or damage the power supply.
When installing a halogen bulb, first switch off the power supply, do not touch the bulb or the lamp bowl with your hand. The halogen bulb is made of high-temperature resistant quartz glass. If it is stained with hands or oil, it will make the quartz glass tarnish, turn white and cloudy, reduce its brightness, shorten its service life, and even break its glass shell. If you accidentally touch it, please wipe it off with alcohol.
When the halogen bulb is lit, the temperature at the seal should not exceed 350 degrees, otherwise the service life of the halogen bulb will be shortened, and therefore the ventilation and heat dissipation conditions of the halogen lamp must be good.
When the halogen bulb is lit, avoid blowing cold air directly to the bulb. Therefore, if a light source cooling fan is installed, most of them should be in the form of outward pumping.
When the halogen bulb is on or after the light is just switched off, the temperature of the bulb will still be very high, and must never be touched by hand.
Halogen lamps should not be turned on/off frequently, otherwise their service life will be significantly shortened. It is recommended to first adjust the light source to the darkest every time before it is turned on or off.

Xenon Light

Xenon lamp light source is a kind of electric light source that emits light in a quartz glass tube by using an inert gas helium discharge. The xenon lamp radiation spectrum energy is close to the daylight distribution, and its color temperature is about 6000K. Xenon lamp is a continuous spectrum, and its spectral energy distribution is almost unchanged during its service life. The consistency of its optical and electrical parameters is good, and the influence of its working state is less affected by changes in external conditions.
The xenon lamp can achieve stable light output instantaneously after being lit, and can be reignited instantaneously after being put out.
Xenon lamp has strong light intensity, large luminous flux, the lamp service life is not lower than 1000H. The disadvantage is that its light effect is relatively low, and the potential gradient is relatively small.
Xenon lamps used in microscopes are generally point sources, and are used by connecting optical fibers.

Precautions:
The sharp protrusion at the rear end of the bulb is the bulb seal, which is relatively fragile and must not be hit.
Before starting the machine and during the running of the illuminator or light source, it must be confirmed that the fan is in working condition. If the fan fails, it is strictly forbidden to start the machine.
When the light source is running, it is forbidden to move.
When the light source is running, do not look directly at the light exit. If you need to observe the spot condition, be sure to wear protective glasses.
When the light source is running, do not touch the surface of the heat sink and the surface of the filter to avoid burns.
Pay attention to the cleaning of the working environment to prevent small objects from falling in through the cooling holes above the light box.

Mercury Light

Mercury lamps are generally referred to as high-pressure mercury lamps. High-pressure mercury lamps are also known as ultra-high pressure mercury lamps. The bulbs are made of quartz glass, filled with mercury. A metallized concave mirror is mounted at the back of the bulb portion, and a collecting lens is mounted on the front side. Mercury evaporation occurs through the discharge between the two electrodes, the gas pressure in the ball rises rapidly, and the mercury vapor pressure can reach 105-106 Pa, that is, 1 ~ 10 atmospheres.

It can provide a very good continuous band visible light spectrum, and provide also rich ultraviolet and blue violet light that can excite various types of fluorescent substances, making it a relatively ideal source for fluorescence microscope.
The mercury lamp has a large output power. The electrode temperature can reach 2000°C during operation, and the temperature of the lamp can reach 600°C. Therefore, a large amount of heat energy is emitted, and the lamp chamber must have good heat dissipation conditions and need to be cooled.

Precautions:
After the high-pressure mercury lamp is extinguished, it cannot be turned off immediately after igniting the bulb, so as to prevent the mercury from evaporating incompletely and damaging the electrode. It takes a period of time from start-up to normal operation, usually 5~10 minutes. After the lamp is extinguished, it must wait for cooling before restarting, generally waiting about 8-15 minutes, or read the instructions. The shorter the working time is after star-up, the shorter the service life of the bulb will be, and therefore minimize the number of starts as much as possible during use.
When the bulb is in use, its luminous efficiency is gradually reduced. The average service life of the 200W ultra-high pressure mercury lamp is about 200 hours. When replacing the bulb, please refer to the timer of the lamp, or do a log and record the usage time of the lights.
If the bulb explodes, you must leave the room for one hour for ventilation, and wait for the harmful gases in the bulb to dissipate before returning to the room to replace the bulb.
Ultraviolet high pressure lamps are harmful to the skin and eyes, and should avoid direct exposure.
When the ultraviolet high-pressure lamp is burning, the temperature of the pipe wall is very high, so don’t touch it to avoid burns.
Do not touch the light-emitting part of the lamp by hand. Wipe the light-emitting part of the lamp with a piece of dry cloth or alcohol before use.

Fluorescence Light

Also called fluorescence lamp.
Conventional fluorescent lamp, that is, low-pressure mercury lamp, uses low-pressure mercury vapor to emit ultraviolet light after being powered up, thereby causing the phosphor to emit visible light.
The light synthesized by the red, green and blue primary colors is a kind of high color rendering sunlight color, the color temperature coverage can reach 2500K-6500K, the color rendering index is about 85, close to the sunlight color (the color rendering index of sunlight R=100), with high luminous efficiency, and average luminous efficiency above 80lm / W, about 5 times that of incandescent lamps, known as high-efficiency energy-saving fluorescent lamp, making its lighting much closer to daylight effect, especially some applications that require good color reproduction and vivid colors.
Fluorescent lamps are characterized by good color rendering, low light decay and long life of light source, but with complex structure, large volume and high cost. Therefore, a wide range of common applications of fluorescent lamps are being replaced by LEDs and the like.
Common fluorescent lamps are: straight tube shape, single U shape, double U shape, ring shape, etc., suitable for different illumination source requirements.

Strobe phenomenon: when the light source is driven by AC or pulsed DC, the luminous flux, illuminance or brightness will change correspondingly with the periodic variation of the current amplitude, forming a stroboscopic flash. Generally, the flicker can be divided into visible flicker and invisible flicker according to human perception. When the frequency is greater than 100Hz, the human eye cannot perceive the flickering phenomenon, but still causes eye fatigue, headache, etc. When shooting with a camera or a digital camera, the image may appear rippled due to the difference in sampling frequency.

Total Magnification

Total magnification is the magnification of the observed object finally obtained by the instrument. This magnification is often the product of the optical magnification and the electronic magnification.
When it is only optically magnified, the total magnification will be the optical magnification.

Total magnification = optical magnification X electronic magnification
Total magnification = (objective X photo eyepiece) X (display size / camera sensor target )

Eyepiece Optical Magnification

Eyepiece optical magnification is the visual magnification of the virtual image after initial imaging through the eyepiece. When the human eye observes through the eyepiece, the ratio of the tangent of the angle of view of the image and the tangent of the angle of view of the human eye when viewing or observing the object directly at the reference viewing distance is usually calculated according to 250 mm/focal length of eyepiece.
The standard configuration of a general microscope is a 10X eyepiece.
Usually, the magnification of the eyepiece of compound microscope is 5X, 8X, 10X, 12.5X, 16X, 20X.
As stereo microscope has a low total magnification, its eyepiece magnification generally does not use 5X, but can achieve 25X, 30X and other much bigger magnification.

Built-in Objective Magnification

The objective of a stereo microscope is mostly built-in objective, which is usually mounted in the microscope body, and it is one or a set of lenses closest to the object to be observed.
When not marked, the built-in objective is 1X.

Numerical Aperture (N.A.)

Numerical aperture, N.A. for short, is the product of the sinusoidal function value of the opening or solid angle of the beam reflected or refracted from the object into the mouth of the objective and the refractive index of the medium between the front lens of the objective and the object.
Simply speaking, it is the magnitude of the luminous flux that can be brought in to the mouth of the objective adapter, the closer the objective to the specimen for observation, the greater the solid angle of the beam entering the mouth of the objective adapter, the greater the N.A. value, and the higher the resolution of the objective.
When the mouth of the objective adapter is unchanged and the working distance between the objective and the specimen is constant, the refractive index of the medium will be of certain meaning. For example, the refractive index of air is 1, water is 1.33, and cedar oil is 1.515, therefore, when using an aqueous medium or cedar oil, a greater N.A. value can be obtained, thereby improving the resolution of the objective.

Formula is：
N.A. = refractive index of the medium X sin solid angle of the beam of the object entering the front lens frame of the objective/ 2

Numerical aperture of the objective. Usually, there is a calculation method for the magnification of the microscope. That is, the magnification of the microscope cannot exceed 1000X of the objective. For example, the numerical aperture of a 100X objective is 1.25, when using a 10X eyepiece, the total magnification is 1000X, far below 1.25 X 1000 = 1250X, then the image seen in the eyepiece is relatively clear; if a 20X eyepiece is used, the total magnification will reach 2000X, much higher than 1250X, then eventhoughthe image actually seen by the 20X eyepiece is relatively large, the effect will be relatively poor.

Objective Adjustable Range

Objective adjustable range refers to that the objective front focal length is adjustable within a certain range. When the microscope is in focus and the observed object changes, refocus becomes necessary.
This is a complementary focusing method in surgical microscopes and certain kinds of industrial applications where it is not desirable to change the position of the microscope after the first focus.

UV Transmittance

UV transmittance is the ratio of the transmitted radiant energy flux to the incident radiant energy flux of the light in the UV band. The wavelength of UV radiation is shorter than that of violet light, and its wavelength range is about 10-380 nm (nanometer).

VIS Transmittance

VIS transmittance is the ratio of the transmitted radiant energy flux to the incident radiant energy flux of the light in the visible range. Visible light radiation is a radiation thatdirectly induces vision,and its wavelength range is about 380-780 nm (nanometer) (or 400-760 nm)

NIR Transmittance

NIR transmittance is the ratio of the transmitted radiant energy flux to the incident radiant energy flux of the light in the infrared band. The wavelength of infrared radiation is longer than that of red light, and its wavelength range is about 0.78-300 um (micron).

Nosepiece with Slot

The nosepiece has a slot for mounting polarizers, filters and other devices.

Inclination on Vertical Direction

Conventional microscopic observation is to observe the observed object from top to bottom at a vertical angle of 90 degrees. Inclination on vertical direction observation is to observe from an angle of inclination direction based on the needs of the object to be observed, so as to see more suitable feature points of the observed object.
Inclination observation often has ergonomic requirements that allow the observer to adjust the angle at will, and using the microscope in a more comfortable position and sitting posture can help reduce fatigue.
In general, all inclination observations are to use microscope with low magnification, which requires a larger field of view and depth of field, otherwise the focusing will be more difficult.

System Optical Magnification

The magnification of the objective lens refers to the lateral magnification, it is the ratio of the image to the real size after the original image is magnified by the instrument. This multiple refers to the length or width of the magnified object.
System optical magnification is the product of the eyepiece and the objective lens (objective lens zoom set) of the optical imaging part within the system.
Optical magnification = eyepiece multiple X objective lens/objective lens set

The maximum optical magnification of the microscope depends on the wavelength of the light to which the object is illuminated. The size of the object that can be observed must be greater than the wavelength of the light. Otherwise, the light cannot be reflected or transmitted, or recognized by the human eye. The shortest wavelength of ultraviolet light is 0.2 microns, so the resolution of the optical microscope in the visible range does not exceed 0.2 microns, or 200 nanometers. This size is converted to the magnification of the microscope, and it is the optical magnification of 2000X. Usually, the compound microscope can achieve 100X objective lens, the eyepiece is 20X, and the magnification can reach 2000X. If it is bigger, it will be called "invalid magnification", that is, the image is large, but the resolution is no longer increased, and no more details and information can be seen.

System Electronic Magnification

The electronic magnification usually refers to the lateral magnification, that is, the ratio of the magnification of the image of the object being observed after passing through the image sensor and the terminal display. This magnification is the digital image magnification and it does not improve the resolution of the original image to the object being observed.
Electronic magnification = display size (diagonal) / camera sensor target (diagonal)

(Appendix) Different Camera Sensor Target Diagonal Conversion Table

System Field of View

Field of View, is also called FOV.
The field of view, or FOV, refers to the size of the object plane (i.e., the plane of the point of the observed object perpendicular to the optical axis), or of its conjugate plane (i.e., object to primary image distance), represented by a line value.
System field of view is the size of the actual diameter of the image of the terminal display device of the instrument, such as the size of the image in the eyepiece or in the display.

Field of view number refers to the diameter of the field diaphragm of the objective lens, or the diameter of the image plane formed by the field diaphragm.
Field of view number of objective lens = field of view number of eyepiece / (objective magnification / mechanical tube length)

Large field of view makes it easy to observe the full view and more range of the observed object, but the field of view (FOV) is inversely proportional to the magnification and inversely proportional to the resolution, that is, the larger the field of view, the smaller the magnification, and also the lower the resolution of the object to be observed.
There are usually two ways to increase the field of view, one is to replace with an objective lens of a smaller multiple, or to replace with an eyepiece of a smaller multiple.

Zoom Range

Zoom in zoom microscope means to obtain different magnifications by changing the focal length of the objective lens within a certain range through adjustment of some lens or lens set while not changing the position of the object plane (that is, the plane of the point of the observed object perpendicular to the optical axis) and the image plane (that is, the plane of the image imaging focus and perpendicular to the optical axis) of the microscope.
Zoom range refers to the range in which the magnification is from low to high. In the zoom range of the microscope, there is no need to adjust the microscope knob for focusing, and ensure that the image is always clear during the entire zoom process.
The larger the zoom range, the stronger the adaptability of the range for microscope observation, but the image effects at both ends of the low and high magnification should be taken into consideration, the larger the zoom range, the more difficult to design and manufacture, and the higher the cost will be.

Zoom Ratio

Zoom ratio is the ratio of the maximum magnification / the minimum magnification. Expressed as 1: (ratio of maximum magnification / minimum magnification). If the maximum magnification is 4.5X, the minimum magnification is 0.7X, then the zoom ratio = 4.5 / 0.7 = 6.4, the zoom ratio will be 1:6.4.
Zoom ratio is obtained by the intermediate magnification group of the microscope. When the magnification is increased or decreased by using other objective lenses, the zoom ratio does not change accordingly.

Magnification Detent

In the body of zoom microscope, zooming is continuous. When rotating to a certain position, generally an integral multiple, a positioning structure or detent is added, which has a distinct hand feel during the zooming process, and stops at this position.
When measuring, or testing by factory for unified standard magnification, a magnification detent device can avoid the error caused by the inaccurate multiple positioning of the optical magnification.

Eye Tube Angle

Usually the Microscope Eyetube is 45°, some is 30°, Tiltable Eyetube Angle design of a microscope is also known as the ergonomics microscope.
0-30° or 0-45° is an ergonomic design. When the mechanical tube length / focal length of the tube of the microscope is relatively big, the microscope is relatively high, and the user's height or the seat of the work desk is not suitable, long-term use of microscope may cause sitting discomfort.
Eyepiece tube with variable angle can freely adjust the angle without lowering the head. Especially when it is close to 0 degree and the human eye is close to horizontal viewing, long-time or long-term use can avoid fatigue damage to the cervical vertebra.

Erect/Inverted Image

After imaging through a set of objective lenses, the object observed and the image seen by the human eye is inverted. When the observed object is manipulated, move the specimen or object, the image will move in the opposite direction in the field of view. Most of the biological microscopes are reversed-phase designs.
When needing to operate works with accurate direction, it is necessary to design it into a forward microscope. Generally stereo microscopes and metallurgical microscopes are all of erect image design.
When observing through the camera and display, the erect and inverted image can be changed by the orientation of the camera.

Interpupillary Adjustment

The distance between the two pupils of the human eye is different. When the image of exit pupil of the two eyepieces of the microscope are not aligned with the entry pupil of the eye, the two eyes will see different images, which can cause discomfort.
Adjust the distance between the two eyepieces, to accommodate or adapt to the pupil distance of the observer's eyes. The adjustment range is generally between 55-75mm.

Eye Tube Diopter Adjustable

For most people, their two eyes, the left and the right, have different vision; for the eyepiece tube, the eyepoint height of the eyepiece can be adjusted to compensate for the difference in vision between the two eyes, so that the imaging in the two eyes is clear and consistent.
The range of adjustment of the eyepiece tube is generally diopter plus or minus 5 degrees, and the maximum differential value between the two eyepieces can reach 10 degrees.

Monocular adjustable and binocular adjustable: some microscopes have one eyepiece tube adjustable, and some have two eyepiece tubes adjustable. First, adjust one eyepiece tube to the 0 degree position, adjust the microscope focusing knob, and find the clear image of this eyepiece (when the monocular adjustable is used, first adjust the focusing knob to make this eyepiece image clear), then adjust the image of another eyepiece tube (do not adjust the focusing knob again at this time), repeatedly adjust to find the clear position, then the two images are clear at the same time. For this particular user, do not adjust this device anymore in the future.
As some microscopes do not have the vision adjustment mechanism for the eyepiece tube, the vision of the two eyes are adjusted through the eyepiece adjustable.

Image Port Switch Mode

The third eyepiece splitting in the trinocular microscope is to borrow one of the two sets of eyepiece optical paths as the photographic light path. The beam split prism or beam splitter can reflect part of the image light to the eyepiece, and part passes through to the third eyepiece photographic light path, such a trinocular microscope is called trinocular simultaneous imaging microscope, or true-trinocular.
The beam split prism or beam splitter of the trinocular simultaneous imaging microscope or true-trinocular often has different splitting modes, such as 20/80 and 50/50, etc. Usually, the former is the luminous flux ratio of the eyepiece optical path, and the latter is the luminous flux ratio of the photographic optical path.

The advantage of true-trinocular is that, the real three optical paths can be imaged at the same time, and are not affected by the simultaneous use of the eyepiece observation and the photographic optical path (display). The disadvantage is that, because of the reason of the splitting, the image light of the photography is only a part. In theory, the image effect will be affected, and the effect is more obvious in the binocular eyepiece observation. If viewed closely, one will find that the eyepiece of the light path is relatively dark. However, in the current optical design and materials, the impact on the actual work is not very big, especially in the observation of low magnification objective lens, it has basically no effect at all, and therefore used by many people.

Number of Microscope Head

The number of microscope head refers to the number of the observation tubes when there is more than one observing through the microscope. By using prism splitting or optical bridge assemblage, when one person operates, many people can observe the image in the same field of view.
When the number of observation heads is relatively more, since each optical path needs to be split from the main optical path, so the more the number of observation heads, the darker the field of view will be.
Microscope on the main operating position often has an indicator, usually an indicator light generated by the power source, to demonstrate some special observation points and locations.
In teaching or multi-person demonstration, the method of camera connected to the display is often used; and by observing the image on the screen, it achieves the teaching and presentation effect, and the cost is low and the effects are good. But in some special industrial applications, such as surgery under the microscope, biological cell analysis under the microscope, factory assembly, welding, etc., multi-person observation of the microscope can better display the completely realistic mirroring effect, and is also irreplaceable.

Eyepiece Field of View

The eyepiece field of view is the diameter of the field diaphragm of the eyepiece, or the diameter of the image plane of the field diaphragm imaged by the field diaphragm.
The diameter of a large field of view can increase the viewing range, and see more detail in the field of view. However, if the field of view is too large, the spherical aberration and distortion around the eyepiece will increase, and the stray light around the field of view will affect the imaging effect.

Objective Optical Magnification

The finite objective is the lateral magnification of the primary image formed by the objective at a prescribed distance.

Infinite objective is the lateral magnification of the real image produced by the combination of the objective and the tube lens.
Infinite objective magnification = tube lens focal length (mm) / objective focal length (mm)

Lateral magnification of the image, that is, the ratio of the size of the image to the size of the object.
The larger the magnification of the objective, the higher the resolution, the smaller the corresponding field of view, and the shorter the working distance.

Objective Type

In the case of polychromatic light imaging, the aberration caused by the light of different wavelengths becomes chromatic aberration. Achromatic aberration is to correct the axial chromatic aberration to the two line spectra (C line, F line); apochromatic aberration is to correct the three line spectra (C line, D line, F line).
The objective is designed according to the achromaticity and the flatness of the field of view. It can be divided into the following categories.

Achromatic objective: achromatic objective has corrected the chromatic aberration, spherical aberration, and comatic aberration. The chromatic portion of the achromatic objective has corrected only red and green, so when using achromatic objective, yellow-green filters are often used to reduce aberrations. The aberration of the achromatic objective in the center of the field of view is basically corrected, and as its structure is simple, the cost is low, it is commonly used in a microscope.

Semi-plan achromatic objective: in addition to meeting the requirements of achromatic objective, the curvature of field and astigmatism of the objective should also be properly corrected.
Plan achromatic objective: in addition to meeting the requirements of achromatic objectives, the curvature of field and astigmatism of the objective should also be well corrected. The plan objective provides a very good correction of the image plane curvature in the field of view of the objective, making the entire field of view smooth and easy to observe, especially in measurement it has achieved a more accurate effect.

Plan semi-apochromatic objective: in addition to meeting the requirements of plan achromatic objective, it is necessary to well correct the secondary spectrum of the objective (the axial chromatic aberration of the C line and the F line).
Plan apochromatic objective: in addition to meeting the requirements of plan achromatic objective, it is necessary to very well correct the tertiary spectrum of the objective (the axial chromatic aberration of the C line, the D line and the F line) and spherochromatic aberration. The apochromatic aberration has corrected the chromatic aberration in the range of red, green and purple (basically the entire visible light), and there is basically no limitation on the imaging effect of the light source. Generally, the apochromatic aberration is used in a high magnification objective.

Objective Working Distance

The objective working distance is the vertical distance from the foremost surface end of the objective of the microscope to the object surface to be observed.
Generally, the greater the magnification, the higher the resolution of the objective, and the smaller the working distance, the smaller the field of view. Conversely, the smaller the magnification, the lower the resolution of the objective, and the greater the working distance, and greater the field of view.
High-magnification objectives (such as 80X and 100X objectives) have a very short working distance. Be very careful when focusing for observation. Generally, it is after the objective is in position, the axial limit protection is locked, then the objective is moved away from the direction of the observed object.
The relatively greater working distance leaves a relatively large space between the objective and the object to be observed. It is suitable for under microscope operation, and it is also easier to use more illumination methods. The defect is that it may reduce the numerical aperture of the objective, thereby reducing the resolution.

Objective Resolution

Objective resolution is the distance that can be distinguished between the two mass points on the object plane, or the number of pairs that can be distinguished within 1mm of the image place. Usually, its unit is expressed as the number of pairs/mm.
In general, the greater the magnification, the higher the resolution.
Under the same objective magnification, the greater the numerical aperture (N.A.) of the objective, the higher the resolution of the objective. Numerical aperture (N.A.) is the most important technical index reflecting the resolution of the objective.
The objective is located at the forefront of the object being observed. When the objective magnifies and forms an image, the rear eyepieces and other equipment are to magnify again. When the eyepiece magnifies enough, one may only get a large enough but blurred image. Therefore, if the front-end objective cannot distinguish, neither can the rear device or equipment distinguish againmore information. The objective is the most important part of a microscope.

Objective Cover Glass Thickness

The thickness of the cover glass affects the parfocal distance of the objective. Usually, in the design of the focal length of the objective,the thickness of the cover glass should be considered, and the standard is 0.17mm.

Objective Immersion Media

The use of different media between the objective and the object to be observed is to change and improve the resolution. For example, the refractive index of air is 1, water is 1.33, and cedar oil is 1.515. Therefore, when using an aqueous medium or cedar oil, a greater N.A. value can be obtained, thereby increasing the resolution of the objective.
Air medium is called dry objective, where oil is used as medium iscalled oil immersion objective, and water medium is called water immersion objective.
However, because of the working distance of the objective, when the working distance of the objective is too long, the use of liquid medium will be relatively more difficult, and it is generally used only on high magnification objective having a shorter working distance, such as objectives of 60X, 80X and 100X.

When using oil immersion objective, first add a drop of cedar oil (objective oil) on the cover glass, then adjust the focus (fine adjustment) knob, and carefully observe it from under the side of the objective of the microscope, until the oil immersion objective is immersed in the cedar oil and close to the cover glass of the specimen, then use the eyepiece to observe, and use the fine focus knob to lift the tube until the clear imageof the specimen is clearly seen.
The cedar oil should be added in an appropriate amount. After the oil immersion objective is used, it is necessary to use a piece of lens wiping tissue to dip xylene to wipe off the cedar oil, and then wipe dry the lens thoroughly with a lens wiping tissue.

Objective Iris Diaphragm

The objective iris diaphragm is a device that is perpendicular to the optical axis and limits the aperture of the light within the objective. In general, the diaphragm mounted on the objective is an aperture diaphragm, that is, the luminous flux is changed without changing the field of view. When the clear aperture is changed, the imaging changes significantly, and the resolution or depth of field of the objective can be changed.

Phase Contrast Objective

Phase contrast objective is an objective applied to phase contrast microscope. Phase contrast objective needs to be used in conjunction with phase contrast ring plate matching the objective magnification. It is divided into positive phase contrast objective and negative phase contrast objective.
Phase contrast objective is a kind of objective equipped with phase plate which is mounted on the back image focal point of the objective, and its purpose is to absorb part of the light,extend the optical path of part of the light, or delay the phase of part of the direct or diffracted light passing through the phased annular diaphragm, producing a phase difference that makes the various structural features clearer.

D/BD Objective

Bright field objectives are used in bright field microscopy to allow direct light topass through the objective aperture and illuminate the background of the visible image. Objectives not labeled are generally bright field objectives.
Dark field objectives are used in dark field microscopy to prevent direct light from passing through the aperture of the objective, thus giving a black background that makes the details of the image clearer and brighter.

Ring Adapter with Cover Glass

When the object to be observed by the microscope has high temperature, corrosive solution or volatile gas, welding fumes, a ring adapter with glass can be used to protect the lens surface and isolate these factors that are destructive to the surface coating of the microscope objective.
The glass of the ring adapter is generally optical glass, and it does not affect the imaging of the microscope, but because of the thickness of the glass, the working distance of some of the microscopes may be slightly increased.

Stand Throat Depth

Stand throat depth, also known as the throat depth, is an important parameter when selecting a microscope stand. When observing a relatively large object, a relatively large space is required, and a large throat depth can accommodate the object to move to the microscope observation center.

Mechanical Tube Length

For objective lens design of finite microscope, its mechanical tube length is the distance from the objective nosepiece shoulder of the objective lens to the eyepiece seat in the tubes, that is, the eyepiece shoulder.

There are two standards in the traditional microscope structure, namely, DIN and JIS. DIN (Deutsches Institute fur Normung) is a popular international standard for microscopes, using 195mm standard conjugate distance (also known as object to primary image distance, 36mm objective lens parfocal distance, and 146.5mm optical tube length.
JIS (Japanese Industrial Standard) is a standard adopted by some Japanese manufacturers, using 160mm standard conjugate distance (also known as object to primary image distance), 45mm objective lens parfocal distance), and 150mm optical tube length.

Using the same microscope standard design, the objective lenses can be used interchangeably.

Focusing Knob Tightness Adjustable

Different microscope bodies, different human operations, and different requirements for observation and operation, all require adjustment of the pre-tightening force of the stand that support microscope body.
Facing the stand just right, use both hands to reverse the force to adjust the tightness. (face the knob of one side just right, clockwise is to tighten, counterclockwise is to loosen)
In general, after long-time use, the knob will be loose, and adjustment is necessary.

Spring Mounted Objective

The front end of the objective is equipped with a spring device. When the working distance of the objective is too short, focusing can easily make the objective contact the object to be observed, thereby damaging the object to be observed or the front lens. At this time, the spring acts to recover the front end of the objective lens. It is usually used on high magnification objectives with very short working distances.

Tube Lens Focal Length

The tube lens focal length is the focal length from the tube lens to the intermediate image plane of the design of infinite microscope, and its typical ranging is from 160 to 200 mm, depending on different manufacturers.

Z-Axis Resolution

See XY Measurement Resolution Z-Axis Resolution

Coupler Magnification

Coupler magnification refers to the line field magnification of the coupler/C-mount-adapter. With different magnifications of the adapter lens, images of different magnifications and fields of view can be obtained. The size of the image field of view is related to the sensor size and the coupler/C-mount-adapter magnification.

Camera image field of view (mm) = sensor diagonal / coupler/C-mount-adapter magnification.

For example: 1/2 inch sensor size, 0.5X coupler/C-mount-adapter coupler, field of view FOV (mm) = 8mm / 0.5 = 16mm.
The field of view number of the microscope 10X eyepiece is usually designed to be 18, 20, 22, 23mm, less than 1 inch (25.4mm). Since most commonly used camera sensor sizes are 1/3 and 1/2 inches, this makes the image field of view on the display always smaller than the field of view of the eyepiece for observation, and the visual perception becomes inconsistent when simultaneously viewed on both the eyepiece and the display. If it is changed to a 0.5X coupler/C-mount-adapter, the microscope image magnification is reduced by 1/2 and the field of view is doubled, then the image captured by the camera will be close to the range observed in the eyepiece.
Some adapters are designed without a lens, and their optical magnification is considered 1X.

Image Sensor Size

The size of the CCD and CMOS image sensors is the size of the photosensitive device. The larger the area of the photosensitive device, the larger the CCD/CMOS area; the more photons are captured, the better the photographic performance; the higher the signal-to-noise ratio, the larger the photosensitive area, and the better the imaging effect.
The size of the image sensor needs to match the size of the microscope's photographic eyepiece; otherwise, black borders or dark corners will appear within the field of view of observation.

Camera Resolution

Resolution of the camera refers to the number of pixels accommodated within unit area of the image sensor of the camera. Image resolution is not represented by area, but by the number of pixels accommodated within the unit length of the rectangular side. The unit of length is generally represented by inch.

Camera Signal Output Port

Digital signals output: USB 2.0, USB3.0; 15 Pin VGA; Firewire Port; HDMI; VGA; Camera Link etc.
Analog signal output: BNC; RCA; Y-C etc.
In addition, some cameras store and output images in the form of a memory card. Usually, industrial cameras often have several output modes on one camera for convenience purposes.

Camera Lens Mount

Industrial camera adapters are usually available in three types:
1. C-Mount: 1" diameter with 32 threads per inch, flange back intercept 17.5mm.
2. CS-Mount: 1" diameter with 32 threads per inch, flange back intercept 12.5mm.
CS-Mount can be converted to a C-Mount through a 5mm spacer, C-mount industrial camera cannot use the CS-mount lens.
3. F-Mount: F-mount is the adapter standard of Nikon lens, also known as Nikon mouth, usually used on large-sized sensor cameras, the flange back intercept is 46.5mm.

Transmission Frame Rate

Frame rate is the number of output of frames per second, FPS or Hertz for short. The number of frames per second (fps) or frame rate represents the number of times the graphics process is updated per second.

Due to the physiological structure of the human eye, when the frame rate of the picture is higher than 16fps, it is considered to be coherent, and high frame rate can make the image frame more smooth and realistic. Some industrial inspection camera applications also require a much higher frame rate to meet certain specific needs.
The higher the resolution of the camera, the lower the frame rate. Therefore, this should be taken into consideration during their selection. When needing to take static or still images, you often need a large resolution. When needing to operate under the microscope, or shooting dynamic images, frame rate should be first considered. In order to solve this problem, the general industrial camera design is to display the maximum frame rate and relatively smaller resolution when viewing; when shooting, the maximum resolution should be used; and some cameras need to set in advance different shooting resolutions when taking pictures, so as to achieve the best results.

Image Sensitive (ISO)

Image sensitive, also known as the ISO value, is the sensitivity of the camera sensor to light, which can be achieved by adjusting the sensitivity of the photosensitive device or combining the photosensitive points.

Camera Crosshairs

Camera crosshairs refers to the preset reference line within the camera, which is used to calibrate various positions on the display. The most commonly used is the crosshair, which is to determine the center position of the camera image, and it is very important in measurement. Some cameras also have multiple crosshairs that can be moved to quickly detect and calibrate the size of the object being viewed. Some crosshairs can also change color to adapt to different viewing backgrounds.

Automatic Focus Function

Automatic focus function is the function that some cameras automatically focus within a certain range. These functions are only that the microscope provides autofocus within a certain depth of field, and as such, it cannot replace the microscope to achieve full automatic focus.
Autofocus is very convenient and suitable to use when observing objects with a certain height at low magnification. After the microscope has adjusted a working distance, it is basically not necessary to adjust the focus of the microscope, especially when repeatedly testing the same sample, the efficiency at the time of detection can be greatly improved.

ESD Safe

Static electricity is a charge that is at static or non-flowing state, and static electricity is formed when charges accumulate on an object or surface.
Static electricity can cause malfunction or mis-opeartion of electronic equipment, resulting in electromagnetic interference. In the electronics industry, static electricity can break down integrated circuits and precision electronic components, causing components to age, and can also absorb dust, causing contamination of integrated circuits and semiconductor components, and reducing production yield. In the plastics industry, static electricity can cause film or membrane not wining up uniformly, film and CD plastic discs contaminated with dust, thereby affecting quality. In industrial production, especially in electronic production and processing and inflammable and explosive production sites, electrostatic protection should be taken seriously.

ESD means "electro-static discharge." For the methods of ESD treatment with respect to microscope and components, electrical conductivity of the metal should be utilized on the one hand, and on the other hand, electrostatic materials, electrostatic coating and other methods of treatment should be adopted to solve the electrostatic problem.
Electrostatic coating is to apply coat that can prevent static electricity. It has electrostatic discharge, dust-proof, mildew-proof, wear-resistant, acid and alkali resistance and other characteristics. The surface of the coating does not generate static electricity or the static electricity is discharged to the safe place through the conductor row.
On some components, electrostatic materials may be applied, such as the microscope knob handle, insulation mat, septum, microscope cover etc.

Compensator

Compensator, also known as color complement, is mainly composed of wave plate. It uses a crystal wafer to perform phase retardation of the polarized light, and measure the order, extinction angle, ductility sign and optical positive and negative of the crystal interference color.

常用的补偿器（波片）有：Commonly used compensators (wave plates) are:
一级红补偿 Full-Wavelength Retardation Plate
1/4波长补偿器1/4 Wavelength Retardation Plate
石英楔补偿器等Quartz Wedge Compensator
石膏试板 Gypsum Test Plate
云母试板 Mica Test Plate
石英试板 Quartz Wedge
倾斜补偿器 Inclined Compensator
勃氏柯勒补偿器 Brace-Koehler Compensator
谢乃尔蒙补偿器 Senarmont Compensator

Aperture Diaphragm

The diaphragm that determines the image plane necessary for imaging through the objective lens is called the aperture diaphragm. All irises of the traditional microscope are aperture diaphragm.

The function of aperture diaphragm is mainly to limit the size of the imaging beam, change the luminous flux, thereby improving the imaging quality. The size of the aperture diaphragm is usually variable, and it is also called iris diaphragm. When the aperture diaphragm lock is too small and the luminous flux of the imaging beam is insufficient, the fraction ratio of the objective lens is low, the imaging will become dark; however, when the aperture diaphragm is too large, there will be strong light in the field of view, and even though viewed from the eyepiece, it may have high resolution, the image on the display will be overexposed.
After replacing the objective lens, the aperture diaphragm should also be adjusted appropriately, rather than adjusting the brightness of the light.
The aperture diaphragm of the transmitted light is generally mounted on the microscope base. The aperture diaphragm of the biological microscope is mounted on the condenser device. On the other hand, the aperture diaphragm of compound microscopes, such as large upright metallurgical or fluorescence microscopes, is generally mounted on the in the coaxial reflection illuminator.
In the use of the aperture diaphragm, it is often necessary to adjust the center of the diaphragm. Generally, it is adjusted together with the condenser. Please refer to the adjustment method of the condenser.

Field Diaphragm

Field diaphragm is also called field of view diaphragm, field of view cutting diaphragm.
The diaphragm that defines the incident angle of view and the exit angle of view of the beam emitted from the object plane, is called field diaphragm.

The main function of the field diaphragm is to limit the range of the image surface size of the observed specimen, and cut off the part of the image edge image plane with relatively poor image quality, so that the entire image plane is clear and flat, but does not affect the resolution of the entire objective lens.
The appropriate adjustment of the field diaphragm can also adjust the glare reflected from the inner wall of the lens tube to improve the imaging contrast and quality. On the eyepiece of the microscope, there is a field-cutting diaphragm. The size of this diaphragm is fixed, and it is also called fixed diaphragm. Its position is between the field lens and the eyepiece, and its function is to limit the emit angle of view of the main beam, so as to make the imaging of the field edge to achieve an ideal effect.
The field diaphragm of most biological microscopes is on the light exit of the base, while the field diaphragm of compound microscopes, such as upright metallurgical and fluorescent microscope, are mounted on the coaxial reflection illuminator.

Stage XY-Axis Position Locking

The stage has a locking function in the XY direction. Generally, it has two functions: one is to maintain the stage positioning and not move after observing the feature points of the object; second, in the process of moving the stage, it should be locked to the 0 position to prevent free movement due to gravity or external force, resulting in stage impact thereby losing accuracy.

Stage Z-Axis Position Limit

Stage Z-axis position limit is a limit locking mechanism of the stage in the Z-axis direction. Generally, when viewed through high magnification objective of the microscope, the working distance space is very small. When the stage moves to a position along the Z axis, the stage is no longer moved upward or downward, so as to avoid the specimen accidentally hits the microscope objective, causing damage to the specimen or the objective.

Stage Scale

The movement of the microscope stage or the mechanical stage can be measured by the moving distance of the ruler, and the size and area of the sample details can be calculated.
The ruler can be divided into main scale and sub-scale. The minimum grid value of the main scale is 1 mm, the integer is measured; the minimum grid value of the sub-scale is 0.9 mm, the decimal is measured. When measuring, if what the main ruler measures is not an integer and therefore one needs to read the decimal of the specimen, align the end point of the sub-scale to the end of this specimen, and then find the scale on the line of main ruler and the sub-ruler, and see which group is the closest, the length of this decimal is the reading of the sub-scale.

XY-Axis Measurement Mode

The XY-axis measurement mode refers to the way the scale used when measuring the XY axis of the stage. For different system, the choice is also different according to the different accuracy and operation requirements, such as mechanical micrometer, capacitance digital display, encoder and so on.

XY-Axis Resolution

XY-axis resolution refers to the minimum value of the measurement that the scale mechanism used can display when measuring the XY-axis. The resolution of the gauge refers to the scale value that can be read directly, also called the division value.
For example, if the division value is 0.001 mm, that is, the resolution is 0.001 mm, and the numerical value of 0.001 mm can be read directly by the scale.

XY-Axis Measurement Accuracy

The XY-axis measurement accuracy refers to the actually obtained measured value when measuring the XY axis. The accurate measurement value can be guaranteed within the range of plus or minus of this accuracy value.
For example, if the measurement accuracy is ±0.002mm, the measured value of the spare part read is X, then the true value range of the part will be
Minimum size: X - 0.002
Maximum size: X + 0.002

Z-Axis Measurement Mode

In terms of method, the Z-axis measurement is consistent with the XY measurement. For details, see the XY-Axis Measurement Mode.

Z-Axis Measurement Accuracy

See XY Measurement Accuracy Z-Axis Measurement Accuracy

Z-Axis Measurement Repeat Positioning Accuracy

See XY Measurement Repeat Positioning Accuracy Z-Axis Measurement Repeat Positioning Accuracy

Light Zone Control

LED is made into light zone for illumination, which allows the light to illuminate the observed object at different positions and angles, so as to better observe different details of the object. There is generally a difference between the incident direction and the incident angle. In the incident direction, there is a combination of different light zone illuminations.
When observing different heights, reflective objects, disordered flat texture scratches and dust, by changing the light zone for illumination, the effect of the detail display can be very obvious.

Eyepoint Type

Eye point refers to the axial distance between the upper end of the metal frame of the eyepiece and the exit of pupil.
The exit of pupil distance of high eyepoint eyepiece is farther than that of the eye lens of the ordinary eyepiece. When this distance is greater than or equal to 18mm, it is a high eyepoint eyepiece. When observing, one does not need to be too close to the eyepiece lens, making it comfort to observe, and it can also be viewed with glasses. Generally, there is a glasses logo on the eyepiece, indicating that it is a high eyepoint eyepiece.

System Working Distance

Working distance, also referred to as WD, is usually the vertical distance from the foremost surface end of the objective lens of the microscope to the surface of the observed object.
When the working distance or WD is large, the space between the objective lens and the object to be observed is also large, which can facilitate operation and the use of corresponding lighting conditions.
In general, system working distance is the working distance of the objective lens. When some other equipment, such as a light source etc., is used below the objective lens, the working distance (i.e., space) will become smaller.

Working distance or WD is related to the design of the working distance of the objective lens. Generally speaking, the bigger the magnification of the objective lens, the smaller the working distance. Conversely, the smaller the magnification of the objective lens, the greater the working distance.
When it is necessary to change the working distance requirement, it can be realized by changing the magnification of the objective lens.

Objective Parfocal Distance

Objective parfocal distance refers to the imaging distance between the objective shoulder and the uncovered object surface (referred to as the “object distance). It conforms to the microscope design, usually 45mm.
The objective of different magnifications of the compound microscope has different lengths; when the distance between the objective shoulder and the object distance is the same, the focal length may not be adjusted when converting to objectives of different magnifications.

Stage Adapter

Stage adapter is a fixing mechanism that connects the stage to the stand or base.

Objective for Mechanical Tube Length

Objective for mechanical tube length is a design parameter of the mechanical tube length of the microscope that the objective is suitable for.

Objective for Focal Length

Objective for focal length is a design parameter of the tube focal length of the microscope that the objective is suitable for.

Camera Maximum Pixels

The pixel is determined by the number of photosensitive elements on the photoelectric sensor of the camera, and one photosensitive element corresponds to one pixel. Therefore, the more photosensitive elements, the larger the number of pixels; the better the imaging quality of the camera, and the higher the corresponding cost.
The pixel unit is one, for example, 1.3 million pixels means 1.3 million pixels points, expressed as 1.3MP (Megapixels).

Adjustable Coupler

On the coupler/C-mount-adapter, there is an adjustable device to adjust the focal length.

Stage Fast Movement

The movement of the general stage is along the direction of the guide rail, driven by screw or friction. The movement is more precise, but it is also very slow. In order to move the stage to a position quickly, a clutch-like switching device can be installed to make the movement out of the screw or the friction path so as to achieve the purpose of rapid movement.

For Camera Sensor Size

For the size of the lens field of view of the coupler/C-mount-adapter, in the design process, the size of the camera sensor imaging target should be considered. When the field of view of the lens is smaller than the target plane of the camera, “black border” and “dark corner” will appear.
The general microscope coupler/C-mount adapters are generally designed for the 1/2" camera targets. When a camera of 2/3 or larger target is used, the “dark corner” phenomenon will appear in the field of view. Especially, at present, DSLR cameras generally use large target plane design (1 inch full field of view), when used for microscopic photographing, the general DSLR camera coupler/C-mount adapter will have “black border”.
Generally, the “dark corner” that appears on the field of view is often that the center of the microscope and the camera are not aligned. Adjust the position of the screw on the camera adapter, or turn the camera adapter to adjust or change the effect.

Trinocular Optical Magnification

When the instrument is conducting electronic image magnification and observation through a camera or the like, the optically magnified portion may not be the optical path that passes through the "eyepiece-objective lens" of the instrument, at this time, the calculation method of the magnification is related to the third-party photo eyepiece passed.
The trinocular optical magnification is equal to the multiplier product of objective lens (objective lens set) and the photo eyepiece

Trinocular optical magnification = objective lens X photo eyepiece

Power Switch Range

In general, objective lens can have 1/3, 2/4, 1/2, 2/4 bodies of several kinds of magnifications. When using the 10X eyepiece, different magnifications such as 10/30, 20/40, 10/20, 20/40, etc. can be obtained respectively, which can be selected by users according to different needs.
A microscope with fixed power switch cannot be stopped in the middle position when transferred, it must be transferred to the exact position of the magnification (with a mechanical positioning), otherwise it cannot be imaged in the middle. During microscope power switch, it is not necessary to adjust the microscope knob for focusing, and the image is guaranteed to be clear.

Objective Screw Thread

For microscopes of different manufacturers and different models, the thread size of their objectives may also be different.
In general, the objective threads are available in two standard sizes, allowing similar objectives between different manufacturers to be used interchangeably.
One is the British system: RMS type objective thread: 4/5in X 1/36in,
One is metric: M25 X 0.75mm thread.

C/CS-Mount Coupler

At present, the coupler/C-mount adapter generally adopts the C/CS-Mount adapter to match with the industrial camera. For details, please refer to "Camera Lens Mount".

Objective Wavelength

Objective wavelength is the permeability of the objective to light of the range of different wavelengths (Wavelength).
The permeability of different wavelengths satisfies the different requirements of the objective tothe object to be observed, such as the commonly used infrared and ultraviolet wave bands.

Stage Mechanical Accuracy

Mechanical accuracy refers to the deviation of the design requirements of the machining accuracy and error from the numerical value obtained after actual processing.
Mechanical accuracy is the difference between the accuracy of the actual geometric parameters (size, shape and position) of the stage after machining and the design requirements. It can also be called machining error. The magnitude of the error reflects the level of mechanical accuracy: the greater the error, the lower the accuracy, and the smaller the error, the higher the accuracy. Generally, in the measurement level requirements, there are corresponding requirements for mechanical accuracy.

Coupler for Microscope Type

Different coupler/C-mount-adapters are suitable for different microscopes. For some, some adapter accessories need to be replaced. See the applicable range of each coupler/C-mount-adapter for details.

White Balance

White balance is an indicator that describes the precision of white color generated in the image when the three primary colors of red, green and blue are mixed, which accurately reflects the color condition of the subject. There are manual white balance and automatic white balance.
White balance of the camera is to "restore white objects to white color under any light source." The chromatic aberration phenomenon occurred under different light sources is compensated by enhancing the corresponding complementary color. Automatic white balance can generally be used, but under certain conditions if the hue is not ideal, options of other white balance may be selected.

XY-Axis Measurement Repeat Positioning Accuracy

Repeated positioning accuracy refers to the degree of consistency of the results obtained when the same part is repeatedly measured under the same conditions. The more consistent the results obtained after statistics, the better the repeat positioning accuracy.
At present, electronic devices such as computers or digital display meters are commonly used to display the measurement results. In the accuracy of the stage, the fixed error portion can be corrected in advance in the software. Therefore, in the measurement accuracy, the data of the repeated positioning accuracy is very important. This data represents the “rigidity” of the stage, that is, the stability and consistency of the measurement.

Camera Video Signal Format

Camera video signal format usually refers to the video output format of the analog signal: NTSC or PAL

Focus Limited

Mostly, at the junction of the compound microscope platform and the body, there is a longitudinal limit mechanism. When the limit mechanism is locked, the platform is prevented from moving up and colliding with the microscope objective, thereby damaging the specimen or destroying the lens.
On its first use, use one specimen, applying 100X or the highest magnification lens, carefully find the clearest image, then lock the axial limit mechanism down, the focus mechanism will remember this position. When the focus is adjusted again to reach this position in the future, it will not go up again, and the platform or specimen will not touch the lens.

Stage Backlight Window Size

Stage backlight window size refers to the size of the window through which the transmitted light passes under the stage on the XY table plane of the stage.
This window is usually covered with a piece of glass. For some stages with accuracy requirements in the XY horizontal direction, the horizontal plane of the glass can be adjusted by the height of the screws on the four corners below, and the consistency with the height of the stage plane is guaranteed.

Auxiliary Objective Optical Magnification

Auxiliary lens, also known as the Barlow lens, is used in conjunction with the imaging lenses or objective lenses of the microscope to extend the focal length of the objective and the magnification and other operating parameters.
The mounting position of the auxiliary objective is at the front end of the objective, and the magnification after adding the auxiliary objective is equal to the objective magnification X the auxiliary objective magnification. In addition to the magnification, the auxiliary objective has also changed the working distance and the field of view of the objective accordingly (field of view).
The greater the magnification of the auxiliary objective, the smaller the corresponding field of view, and the shorter the working distance. On the contrary, the smaller the magnification, the greater the corresponding field of view, and the longer the working distance.
Auxiliary objective is a very useful component in stereo microscope, can be used in conjunction with the space change of the stent use to expand the working space, so that the observer and the microscope are in a more reasonable position. At the same time, for some works such as observation, anatomy, welding, etc. that are relatively close to contact with the object, it can keep the observer in a more comfortable position.

Infinite

Microscopes and components have two types of optical path design structures.
One type is finite optical structural design, in which light passing through the objective lens is directed at the intermediate image plane (located in the front focal plane of the eyepiece) and converges at that point. The finite structure is an integrated design, with a compact structure, and it is a kind of economical microscope.
Another type is infinite optical structural design, in which the light between the tube lens after passing the objective lens becomes "parallel light". Within this distance, various kinds of optical components necessary such as beam splitters or optical filters call be added, and at the same time, this kind of design has better imaging results. As the design is modular, it is also called modular microscope. The modular structure facilitates the addition of different imaging and lighting accessories in the middle of the system as required.
The main components of infinite and finite, especially objective lens, are usually not interchangeable for use, and even if they can be imaged, the image quality will also have some defects.

The separative two-objective lens structure of the dual-light path of stereo microscope (SZ/FS microscope) is also known as Greenough.
Parallel optical microscope uses a parallel structure (PZ microscope), which is different from the separative two-object lens structure, and because its objective lens is one and the same, it is therefore also known as the CMO common main objective.

Finite

With Two Horizontal Knobs

When microscope body changes the magnification, it is realized by adjusting the horizontally placed zoom knob. Because the knob is relatively small, it is therefore easier to zoom and the image is stable.
For most of the dual stereo microscopes, magnification is realized by adjusting the zoom drum or nosepiece below. When the nosepiece is relatively big, frequent operation is more laborious. Magnifying while observing, the microscope may shake, thereby causing eye discomfort for observation.
Using zoom drum or nosepiece type microscope, if there is a ring light under the microscope, the ring light carries the wire, and when magnification conversion is often required, the ring light and the wire will swing along with the magnification, which makes the operation inconvenient. This situation will not occur to zoom with two horizontal knobs.

With the Nosepiece

When the microscope body changes the magnification, it is realized by adjusting the zoom drum or nosepiece. Generally, the lower case of the microscope is used as the zoom drum or nosepiece. When magnification conversion is required, it can be realized by turning the zoom drum or nosepiece.

Compensating

For compensating eyetube, when changing the interpupillary distance, it requires two hands to operate at the same time, with one hand fixing one eyepiece tube, and the other pushing or pulling the other, or both the left and the right hand pushing the two eyetubes at the same time, and changing the position of any one of the eyetube at will.

Siedentopf

For siedentopf eyetube, when changing the interpupillary distance, it requires two hands pushing or pulling the two eyetubes left and right simultaneously, and the two eyepiece tubes or eyetubes will change their position at the same time.

360° Degree Rotatable

The eyepiece of the microscope can have different viewing or observing directions. When the position of the microscope is uncomfortable, the direction of the eyepiece tube of the microscope can be adjusted, to facilitate observation and operation.

Placement method of different viewing angles of the microscope:
General direction: the support column is behind the object to be observed
Reverse direction: the support column is in front of the object to be observed
Lateral direction: the support column is on the side of the object to be observed
Rotating eyepiece tube, different microscopes may have different methods, for some, the direction is confirmed when installing the eyepiece tube of the microscope, for some, by rotating the body of the microscope, and for some, by rotating the support member on the support or holder of the microscope.

Mirror Switch

The third eyepiece in the trinocular microscope is to borrow one set of the two eyepiece optical paths as the photographic light path.
After binocular observation confirming the image, it is necessary to switch one optical path in the eyepiece to the third eyepiece photographic light path through a pull rod. At this time, no imaging can be formed in the eyepiece, which is called 0/100 splitting. When binocular viewing is required, switch it back again, at this time, there is no image in the photographic light path (or display).
The advantage of this splitting design is that, when one set of optical path in the binocular is turned off, what is switched to the photographic optical path is 100% image, and the imaging effect is good; the disadvantage is that, one of the binoculars has no image, and simultaneous trinocular imaging is impossible.

The lever must be pulled open and pushed in so as to switch to the observation image of the eyepiece and the trinocular camera. The eyepiece or the light-passing hole of the trinocular can be directly viewed with the naked eye to see if there is light passing through so as to check whether it is pulled open or closed.

Huygens Eyepiece

The Huygoens eyepiece is composed of two single-sided plano-convex lenses of the same type of glass, consisting of two convex lenses that have not been corrected by chromatic aberration; both are convex toward the objective lens, and the piece close to the eye is called eye piece, for magnification function; the other piece is called field lens, which makes the image brightness uniform.
On the focal plane of the eye lens between the two lenses, there is a diaphragm, which is a parallax diaphragm, which also plays the role of the eyepiece to eliminate the stray light, and can also place the reticle or the pointer on this diaphragm.

Huygens eyepiece has no correction aberration. It is only suitable for use with low and medium achromatic objectives. They are simple in structure and low in cost, which is a commonly used eyepiece for low-end microscopes.
Huygens eyepieces can be used for both observation and photography. When the image formed by the objective lens is within the focus of the eye lens, it becomes a magnified virtual image, microscopic observation can be performed; when the image formed by the objective lens is outside the focus of the eye lens, it becomes magnified real image, microscopic photography can be performed.

Reticle Eyepiece

Reticle eyepiece. The eyepiece focal length (10mm below the eyepiece mounting surface eyepiece shoulder) of the reticle eyepiece is equipped with a reticle for measuring and positioning the object to be observed.
For one microscope, a reticle can be installed only on one eyepiece, and it requires that the two eyepieces should be completely identical. If two are installed, it is generally very difficult to make the two reticles of both the left and the right eyepiece completely overlap, which may cause eye discomfort.
The reticle eyepieces are generally used on 10X and 20X eyepieces.
The mounting dimension of the reticle refers to the size of the inner diameter of the lower end tube of the eyepiece. It requires that the eyepiece that can be equipped with a reticle needs a preset thread and a pressing ring. The reticle is facing up (in the direction of the eyepiece lens), placed flat on the reticle mounting surface of the eyepiece, and screwed in with a pressure ring, and press tight. Ordinary users can also install the reticle on their own as needed.
The reticle is generally made of glass material, and the etched printed surface is the front side. It is mounted on the end close to the eye, which is the position of the eyepiece image plane; when avoiding the use of different reticle, the focal length is different due to the different thickness of the glass, which makes the scribe line of the reticle fall on the unclear image plane position.

The reticle is placed under the eyepiece. When measuring the object, the reticle and the object to be measured are also magnified by the eyepiece, so the actual length of the reading has no relation at all with the magnification of the eyepiece.
When the reticle reads the length value in the eyepiece of the microscope, because the length of the image to be measured passes through the objective lens and reaches the image plane position of the reticle, the length read is actually the length magnified by the objective lens. The real numerical value should be the length of the reading, divided by the numerical value of magnification of the objective lens. If it is the zoom microscope body with also magnification, it should also be divided by the magnification (objective lens X zoom).
In this measurement method, the error mainly lies in that the magnification of the objective lens is not calibrated, and the magnification error of ordinary microscope objective lens can reach +-5%. Therefore, for accurate measurement, it should be used after calibration with the objective micrometer. For the calibration method, please refer to the introduction of “Reticle”.

Pointer Eyepiece

The eyepiece is equipped with a pointer that points to the center position of the imaging plane, and is used to indicate the key viewing position of the object being observed.

Independent Eye Guard

The main function of the eye guard is to block the ambient stray light, which makes it more clearer when observing through the eyepiece. In addition, the height of the eye guard is basically the eyepoint exit pupil distance of the eyepiece, and when the eye is close to the eye guard, it is the exact position for clear imaging.

Fixed Eye Guard

Eye guard installation refers to that the eye guard has been installed on the eyepiece in advance as a component.

Motorized

The nosepiece of a microscope is generally switched manually. A motarized nosepiece is to add an electric motor onto the nosepiece to control switching of the nosepiece through the electric switch, so as to switch the objective used. This device can be added when some microscopes are bulky, switching of the objective needs to be kept steady, and needs to be frequently switched.

Φ76mm Scope Holder

The 76mm stand scope holder is the most popular microscope body adapter size, suitable for stereo microscopes produced by most manufacturers.

Place the microscope body in a 76mm scope holder, tighten with screws to avoid shaking when the microscope is in use.
Because this stand scope holder is very common, some special-sized microscopes can also borrow and use this stand, but only need a specific adapter to connect the microscope body with a diameter of less than 76mm.

Φ39mm Scope Holder

The 39mm scope holder is a scope holder for connecting to a 39mm microscope body.

B＆L Scope Holder

B&L scope holder is a special stand scope holder for connecting to the Bausch & Lomb stereo microscope, under the scope holder there are two metal spring cards to fix the microscope body.

N Adapter

The N adapter is the adapter used to fix the camera and the focus mechanism. The camera usually comes with a standard whitworth thread (a kind of British style thread) adapter. Its specifications are: large diameter 1/4 inch, pitch 20 teeth / inch thick thread, expressed as UNC1/4-20.
The design of the N adapter has two functions: one is to adjust the suitable orientation of the camera, and the other is to extend the camera's throat depth space on the stand to adjust the position of the camera on the stand of the microscope.

Camera Mounting Plate

Camera mounting plate is a connection between the camera and the focusing mechanism. Camera usually comes with a standard whitworth thread (a British type of thread) adapter. Its specifications are: large diameter 1/4 inch, pitch 20 teeth / inch coarse teeth thread, expressed as UNC1/4-20.

Monitor Holder

Monitor holder is a connecting plate between the stand and the display.

Illumination Base

Illumination base is a modular light source component, suitable for microscope stand base that has no light source of itself, and it is usually dedicated components supporting some stands.
Illumination base typically includes at least one bottom lighting, and there are also illumination base that includes the circuit portion of the upper light source.

Coaxial Coarse/Fine Focus

Focus mechanism, the coarse / fine focus knobs are in a coaxial center position, they are connected together by a gear reduction mechanism, which can be coarse/ fine focus adjusted at any time during the entire stroke.
Generally, the coarse focus diameter is relatively big, which is inside close to the body of the microscope, and the fine focus diameter is relatively small, which is outside of the body of the microscope. Coarse focus adjustment is used to quickly move to find the image, and the fine focus adjustment is used to finely adjust the clarity of the image. Generally, the minimum read value of the fine focus adjustment can be accurate to 1 micron, and single circle can reach a stroke of 0.1 mm. Mechanical fine focus plays a very important role in the accuracy of the microscope resolution. If the fine focus accuracy is not enough, or cannot be stabilized at the sharpest focusing position, the image will be out of focus and become blurred.
The tightness of coarse focus is generally adjustable. Generally, on one side of the knob (usually on the right side), there is a textured knob on the inside of the coarse knob, which is tightened if rotated clockwise; and loosened if rotated counterclockwise.

In the process of focusing, direct focusing should not be on the objective of high magnification; instead, find the object of low magnification first, and gradually adjust to high magnification. Usually, the coarse focus knob is rotated first, and when the objective lens is gradually lowered or the platform is gradually rising, find the object, and then adjust with the fine focus, until the object image in the field of view is clear. Generally, when changing from low magnification to high magnification objective, one only need to slightly adjust the fine focus knob to make the object image clear. During the process, the distance between the objective and the specimen should be observed from the side, to understand the critical value of the object distance between the lens and the specimen.
When using a high magnification objective, since the distance between the objective and the specimen is very close, after the image is found, the coarse focus knob cannot generally be used, and the fine focus knob can only be used to avoid excessive distance of movement, damaging the objective and the slide or specimen.

By using the characteristics of the fine focus, the height or thickness of the observed object can be roughly measured under the microscope, such as measuring the thickness of the cell or tissue, the thickness of the cover glass, and the thickness of small objects that cannot be measured by various conventional measuring instruments.
Method of measurement: place the object to be measured at the center of the field of view of the stage. After the image is clearly focused, try to use the highest magnification objective as much as possible, and align the adapter of the top feature point of the object to be measured. After adjusting clear, record the position of scale of the fine focus knob. Then, move the objective down to the adapter of the lowest feature point of the object to be measured, and record the position of scale of the fine focus knob. Then, according to the above fine focus, record the number of rounds of movement, and based on the parameters of conversion of each round into stroke (see the microscope fine focus knob parameters), the number of rounds is converted into the total stroke, which is the height of the object to be measured. If it is repeated a few times for average, a more accurate measurement can be obtained.

None Coaxial Coarse/Fine Focus

The coarse / fine focus knobs are not on a concentric axis, but in different positions of the stand respectively, such a mechanism is often limited by the structure of the microscope.

Dark Field

Bright field illumination is that direct light shining on the object to be observed and the background enters directly into the objective lens, producing a background of a bright image; the dark field corresponds to the bright field, so that the light is obliquely irradiated onto the surface of the sample, and the direct light is not allowed to pass through the aperture of the objective lens, so as to be able to observe object details in a black background.

The light source adopts parallel light, and an annular visor is placed at an appropriate position on the incident light path to cover the central portion of the light. The surrounding light passing through the annular visor is a hollow cylindrical beam and is incident on the vertical illuminator. The vertical illuminator of the dark field illumination is a circular reflector that reflects the cylindrical beam upwards and projects it onto the reflector of the condenser, so that the reflected light is concentrated on the surface of the sample. Since the reflected light is highly tilted, the light cannot enter the objective lens, therefore the field of view is dark. Only in the concave place of the observed object can light enter the objective lens, and the bright white image is reflected in the dark field of view, called "dark field of view " (dark field) illumination.
In most cases, the bright portion of the black-and-white image obtained by dark field illumination is considered to be the black portion of the black-and-white image obtained by bright field illumination.
Dark field illumination improves the contrast of the image, making the color of the image natural and uniform. The angle of the incident beam is extremely large, which increases the effective numerical aperture of the objective lens, and the ability to identify details is higher than that of bright field illumination.
Dark field illumination must ensure that the system is clean, as dust particles can form bright spots in the dark field, which can affect the results of observation.

Kohler Illumination

Kohler illumination: is a secondary imaging illumination that overcomes the shortcoming of direct illumination of critical illumination. After the filament of the light source passes through the condenser and the variable field diaphragm, the filament image falls for the first time in the condenser aperture diaphragm, the condenser forms a second image at the back focus plane position there, so that there is no filament image at the plane of the object to be observed, and the illumination becomes uniform.
During observation, by changing the size of the condenser aperture diaphragm, the light source fills in the entrance pupil of the objective lens, and the numerical aperture of the condenser is matched with the numerical aperture of the objective lens. At the same time, the condenser images the field diaphragm at the plane of the observed object, and the illumination range is controlled by the size of the field diaphragm. Since the thermal focus of Kohler illumination is not at the plane of the object to be observed, the object to be observed will not be damaged even if it is irradiated for a long time.

Achromatic Condenser

Achromatic condenser is a condenser that only corrects the chromatic aberration.

Low Power Condenser

Low power condenser is mainly used together with low magnification objective lens with relatively long focal length.
If the observation is mainly carried out by low magnification objective, low magnification condenser can have much better resolution, flat image surface and good contrast.

Abbe Condenser

Abbe condenser is a kind of bright field condenser, a condenser that can only finitely correct the spherical aberration, but not the chromatic aberration. When the numerical aperture of its objectives is higher than 0.6, Abbe condenser will show chromatic aberration and spherical aberration.

Polarizing Condenser

Polarizing condenser is a condenser used for polarizing microscopes.
Polarizing condenser requires achromatic/aspherical aberration, its lens requires no stress, the uppermost lens is relatively small. Polarizing condenser is usually called conoscope, can be pushed in and out, and it is a kind of shake-out condenser.

Achromatic/Aplanatic Condenser

Achromatic/aplanatic condenser is also known as achromatic-aplanatic condenser.
Condenser that can correct chromatic aberration, spherical aberration, and coma aberration is the best quality condenser among the bright field condensers. It has also a very high numerical aperture, but it is not suitable for objectives below 4 times

Darkfield Condenser

Darkfield condenser is also known as dark ground condenser
Darkfield condenser is a condenser used for dark field microscope. For light emitted from the light source, the direct beam cannot enter the objectives from the condenser, only the reflected light and the diffracted light that are reflected from the spherical surface of the condenser can be irradiated to the specimen details before entering the front lens of the objectives.
The object image produced by the dark field condenser reflects the side image of the object details only in the full dark field of view, thus greatly improving the resolution of the microscope. Darkfield condenser has a very important role, especially when observing the unstained specimens.

Light Adjustable

The brightness of the light source adjustable is very important in the imaging of the microscope. Since the difference of the numerical aperture of the objective lens of high magnification and low magnification is very big, more incident light is needed to achieve a much better resolution when using a high magnification objective lens. Therefore, when observing through a high magnification objective lens, the brightness required is high; when observing through a low magnification objective lens, the brightness required is low.
When observing different objects, or feature points of the same object at different positions, the brightness needs are also different; including the difference of background light or reflection within the field of view of observation, it has a great influence on the effect of observing the object, and therefore one needs to adjust the brightness of the light source according to each object to be observed.
In the light source capable of providing continuous spectrum, such as a halogen lamp, the brightness adjustment of the light not only adjusts the brightness and intensity of the light, but also changes the spectrum emitted by the light source. When the light source is dark, there are many components of red light, and when the brightness is high, there are more blue spectrum. If the required light is strong and the spectrum needs to be changed, the light can be kept at a brighter intensity, which is solved by adjusting the spectrum by adding a color filter.

Take note of the dimming button on the light source, after the On/Off switch is turned on, normally clockwise is to brighten, and counterclockwise is to darken.
If it is adjusted to the lowest brightness, the light source should normally be lit. If the naked eye still can't see the object being illuminated brightly, you need to adjust the brightness knob to a much bigger position.
Generally, there is scale marking on the dimming knob, which is an imaginary number representing the percentage of brightness, or an electronic digital display, giving the brightness of the light source under the same conditions a marking.

CCD

CCD, charge coupled device.
See CCD and CMOS structure comparison table

CMOS

CMOS, or complementary metal oxide semiconductor.
Both CMOS and CCD sensors have their own respective advantages and disadvantages. As a kind of photoelectric conversion sensor, among the current cameras, CMOS is relatively more widely used.

Quartz Glass

Quartz glass slide is a glass slide made of quartz material. Its main component is silica, the content of which is up to 99.99%, and its Mohs hardness is grade seven, with high temperature resistance, low thermal expansion coefficient, thermal shock resistance and good electrical insulation properties. Visible light transmittance can reach more than 85%.

Long Working Distance Condenser

Long working distance condenser is a condenser with relatively long focus. Long working distance condenser is used to observe objects that are relatively far away from the stage, it is especially used on inverted microscopes.

Phase Condenser

Phase condenser is used for the condenser of phase contrast microscope. Because the phase contrast function involves relatively more functional components, the phase condensers of different manufacturers generally are not easily interchangeable.

Full Type

The full type polarizing kit is a complex component embedded in the whole of a polarizing microscope, including polarizer and analyzer, polarizing condenser, specially-made polarizing microscope rotary stage, cross reticle eyepiece, Bertrand lens, and various kinds of compensators etc.
Full type polarizing kit is relative to the simple type polarizing kit, and all the simple type polarizing kits are simple polarizing microscope that is added to the compound microscope using a set of polarizing plates.

Simple Type

All polarizing microscopes use linear polarizers. A polarizer is added to the incident light path, and an analyzer is added to the observation optical path to obtain polarized light for illumination. This kind of accessory that adds polarized illumination to a polarizing microscope is called a simple type polarizing kit. Simple type polarizing illumination can remove the glare and hot spots from images in normal imaging, improving illumination contrast and simplify rotary operation.

Inverted

The main difference between an inverted microscope and an upright microscope is that the objective lens of the inverted microscope is located below the stage and is viewed or observed from the bottom up, while the objective lens of the upright microscope is located above the stage on which the sample is placed, and is viewed or observed from the top down.

The light source of inverted microscopes is generally divided into two forms, one is transmitted light source inverted microscope, and the other is reflection light source inverted microscope.
When observing the petri dish, the focal length of the objective lens of the inverted compound microscope should be longer than that of the upright microscope and be able to pass through the glass thickness of the vessel glass, and the oil lens cannot be used. The focal length of the condenser of the inverted microscope is longer than that of the ordinary upright microscope.
The inverted microscope has a longer and more complicated optical path design. It is suitable for observing adhering or suspending cells and substances in some culture dishes, culture flasks, hanging drop culture plates, and solution vessels in medicine and biology; in addition, when some of the observed objects are bulky and heavy, or the metal observation surface is not proper to be upright or fixed placed, inverted observation will be easy to use; the inverted microscope has lower requirements for sample preparation, no requirement for sample height, convenient and rapid for testing, and also facilitates processing and operation of the sample.

Oil lens are generally not recommended for inverted microscopes, because lens oil tends to flow down the objective lens, and is difficult to operate. Moreover, in an inverted microscope, the working distance of a high-magnification objective lens is generally also very short.

Condenser

Condenser, also known as concentrator, is a converging lens equivalent to a convex lens that focuses illumination light on the object to be observed to enhance the illumination of the object under observation, and to ensure that the objective lens has a certain numerical aperture.
In a transmissive illumination system, condenser is typically placed under the stage. It consists of a condenser lens, a variable diaphragm (iris diaphragm) and a lifting mechanism. The height and horizontal position of the condenser can be adjusted, so that the focus falls on the object to be observed in order to obtain bright illumination.
Simple microscope often has no condenser, but when using an objective with a numerical aperture of 0.40 or above, it is necessary to have a condenser. The number engraved on the frame of the condenser represents the largest numerical aperture (NA), generally between 1.2~1.4. The variable numerical apertures are adjusted by changing the iris diaphragm, to match the numerical aperture of different objective lenses.
It should be noted what the condenser and the diaphragm control is the amount of luminous flux of the light, rather than the brightness or darkness of the light or the wavelength of the light, as the latter needs to adjust the brightness and darkness of the light of the power supply.

By adjusting the size of the condenser’s iris diaphragm , you can change the resolution and contrast of the image. When the diaphragm is too large, exceeding the numerical aperture of the objective lens, the resolution will be improved, but spot can be generated; however, if the diaphragm is too small, the depth of field and the contrast increases, but the illumination light will be insufficient, and the resolution will decrease.
The focus of the condenser is designed about 1.25mm at the upper end of the lens, which falls exactly on the observed specimen. The thickness of the slide used should be between 0.8~1.2mm. Otherwise, the focus of the light is not be at the sample position, which will affect the image effect.
There are many types of condensers. At the same time, based on the size of the numerical aperture of the objectives, the requirements for condensers are also different. Generally, it can be divided into bright field condenser and dark field condenser. All ordinary optical microscopes are equipped with bright field condenser. The bright field condenser can be divided into Abbe condenser, achromatic condenser and shake-out condenser. There are also some special purpose condensers, such as dark field condenser, phase contrast condenser, polarized condenser, differential interference condenser, etc., so as to meet the needs of various microscope observation methods.
There are usually two screws on the condenser that can adjust the center of the condenser and align with the central optical axis of the microscope objective. The fixing screws on the condenser are generally removable, so that the condenser can be removed for cleaning, or replaced with a different condenser.

Condenser adjustment precautions
1. Adjust the vertical position of the condenser
Adjust the field diaphragm and the aperture diaphragm to the minimum, adjust the up and down position of the condenser knob to find a sharp-edged polygon image. If the opening of the diaphragm is too small and the field of view is too dark to find the image, you can zoom in slightly the field diaphragm to find the image.
2. Adjust the center position of the condenser
First open the field diaphragm to the minimum position, see whether the pattern of the polygon of the diaphragm is in the center of the field of view. If not, you can adjust the two centering screws of the condenser. Then slowly zoom in on the field diaphragm, so that the polygon and the edge of the field of view are externally tangent, which is the best working position for the field diaphragm.
3. Adjust the numerical aperture of the condenser and the objectives for matching
The purpose to adjust the numerical aperture of the condenser is to mutually match the numerical aperture of the objectives so as to obtain the best resolution.
On the outer edge of the microscope condenser, there are grading numbers and positioning marks to facilitate the recording of the numerical aperture matching position of the condenser and the objectives. Some condensers do not have marked numbers on the outside, in this case, you can first focus the objective lens, then remove one eyepiece, observe it in the lens tube, and then adjust the size of the aperture diaphragm, so that the aperture diaphragm and the rear objectives display a clear and bright circle, then the numerical apertures of the condenser and the objective lens are matched to each other.

Through the above adjustment, the optical axis of the condenser is aligned with the optical axis of the illumination light path and the imaging light path, thereby achieving the most ideal image observation effect.
After the above condensers are adjusted, it is no longer necessary to adjust again the position of the condenser in future use.

Adjustable Eyepiece

The adjustable eyepiece is between the lens of the eyepiece and the focal plane, with distance adjustable device.
For most people, their two eyes, the left and the right, have different vision. For adjustable eyepieces, the eyepoint height of the eyepiece can be adjusted to compensate for the difference in vision between the two eyes, making the image in the two eyes clear and consistent.
The range of adjustment of the general eyepiece is that the diopter is plus or minus 5 degrees, and the maximum difference between the two eyepieces can reach 10 degrees. Before use, it is generally necessary to adjust both eyepieces to the initial position where the scale is displayed as 0, which is used as a baseline to facilitate up and down adjustment.
The reticle position of the eyepiece is generally 10mm below the fixed position of the eyepiece tube. Because the vision of each person is different, some people may not be able to see the reticle clearly. For adjustable eyepiece, the height of the reticle position can be adjusted to make the reticle and the observed object clear at the same time, this is the advantage of adjustable eyepiece that mounts the diopter adjustment on the eyepiece tube compared with non-adjustable eyepiece.
When non-adjustable eyepiece is equipped with a reticle, if the diopter is adjusted, the reticle will rotate accordingly, thereby affecting the position of the measurement. For adjustable eyepiece, when its diopter is adjusted, its reticle does not rotate.

Calibration

The microscopic images intercepted by the camera are all images obtained after optical magnification of the microscope, which is different from the actual size of the object observed. Calculated according to the microscope magnification, there is optical error on the one hand, and some continuous zooming microscopes have changed in magnification during the zooming process on the other hand. Therefore, the measurement needs to be first calibrated, and calculate the differential value between the size of the image on the display and the size of the real object, which is then stored in the software as a coefficient. When the observed object is measured on the screen, it is automatically multiplied by this coefficient, thereby visually obtaining the accurate measured values.

Calibration method of measuring software scale for calibration of camera:
1. Use a micrometer with numerical scribed lines, place it under the microscope, adjust the image clearly, and fix it on a magnification. The precision and accuracy of the digital reticle of the said micrometer will affect the entire measurement result. Therefore, the micrometer should be calibrated to ensure its accuracy.
2. Click the “Measurement Function” button, open the measurement software function, and enter the measurement page.
3. For different measurement software, there are the difference of dynamic measurement and static measurement: static measurement is to insert the ruler into the frame before the measurement, and intercept the image to be measured and save it to the computer memory. At this time, the picture/frame is fixed, and has been intercepted and stored in the computer memory. During dynamic measurement, the fixed picture is not intercepted, but measured directly in the Live image.
4. The page will display the micrometer screen for observation. At the bottom of the screen, there will be a additional ruler and information line segment.
See （Picture 1）
5. Use the left mouse button to click the ruler line segment, then move the ruler to place the ruler parallel to the micrometer in the picture; then, use the mouse to left click on the left and right endpoints of the ruler line segment to align completely the ruler line segment with the line segment in the actual micrometer.
See （Picture 2）
6. As shown in the figure above, the line segment where the ruler is aligned with the micrometer is 5mm. Then in the set ruler toolbar on the right side of the screen, mark the actual observation size, click Apply, and the setup is complete.
7. Click the ruler name in the ruler save bar on the right, name the ruler under the said objective magnification. It can be as simple as 1 or 1X or other markable name.
See （Picture 3）
8. Repeat 1-7. According to the fact that for different microscopes, different objective lenses can be used, multiple corresponding scales may be set. In the right ruler save column, save multiple scales of different objective magnifications for use when replacing different objective lenses.
See （Picture 4）
9. Change the picture frames obtained by changing different styles and images, setting different resolutions and different objective magnifications. When making measurements, be sure to click on the loading ruler (i.e., the corresponding ruler set in advance) before making measurements. Changing photos and resolutions does not need to calibrate different rulers, but every time after the picture and resolution are changed, it is necessary to click to load the corresponding ruler.
See （Picture 5）

Computer Control

Refers to the use of computer control to adjust the light source switch and brightness. Generally, on the light source, through a standard 5V power source interface and by changing the voltage, the brightness is adjusted.

Swing Out Condenser

When using a low magnification objective (such as 4X), because the field of view is large, the light source cannot fill the entire field of view, the edge of the field of view is partially dark, therefore, the upper lens of the condenser needs to be shaken out of the optical path, so as to meet the needs of large field of view illumination.

Critical illumination

Critical illumination: is an ordinary illumination method. After the light source passes through the condenser, it directly illuminates the surface of the object to be observed. The structure is simple, and the beam is bright and strong.
The light source filament image of the critical illumination coincides with the plane of the object to be observed, which causes the illumination to exhibit non-uniformity, resulting in that the part where there is filament is bright, and the part where there is no filament is dim, hence affecting the quality of the image, especially for higher magnification, higher image quality requirements cannot be achieved.
The remedial method is to place a white or other band of color filters and heat shields in front of the light source to make the illumination uniform, and to avoid damage to the object under observation due to long-term illumination of the light source.