|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.
|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.
|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.
|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.
|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
|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 )
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|Coupler/C-mount adapter is an adapter commonly used for connection between the C-adapter camera (industrial camera) and a microscope.
|On the coupler/C-mount-adapter, there is an adjustable device to adjust the focal length.
|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.
|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.
|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".
|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.
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