Finite. Total Magnification: 40-160X. 10X 16X Eyepiece. 4X 10X Achromatic Objective. Eye Tube Angle: 45°. Eyepiece Field of View: Dia. 11mm. Eyepiece Field of View: Dia. 18mm. XY Stage Travel Distance: 65x50mm. Temperature Control Range: 20~50°C(68~122°F). Temperature Control Stage Dimensions: 150x130x3mm (5.906x5.118x0.118 in. ). Illumination Type: LED Coaxial Transmitted Light. Input Voltage: AC 100-240V 50/60Hz.
Forensics , Blood Analysis
|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.
|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.
|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.
|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.
|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 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.|
|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.
|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.
|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.
|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.
|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.
|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 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.
|Objective for mechanical tube length is a design parameter of the mechanical tube length of the microscope that the objective is suitable for.|
|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.
|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.
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.
|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.|
|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.
|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.
|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.|
|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.
|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.
|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.
|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.|
|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.
|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.
|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.
|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.
|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.
|Microscope Optical Data Sheet|
|P/N||Objective||Objective Working Distance||Eyepiece|
|BM13022221 (10X Dia. 18mm)||BM13022511 (16X Dia. 11mm)|
|Magnification||Field of View(mm)||Magnification||Field of View(mm)|
|1. Magnification=Objective Optical Magnification * Body Magnification * Eyepiece Optical Magnification|
|2. Field of View=Eyepiece Field of View /（Objective Optical Magnification*Body Magnification）|
|3. The Darker background items are Standard items, the white background items are optional items.|
|Packaging Type||Carton Packaging|
|Packaging Material||Corrugated Carton|
|Packaging Dimensions(1)||32x28x43cm (12.60x11.02x16.93″)|
|Packaging Dimensions(2)||31x21x10.5cm (12.205x8.268x4.134″)|
|Packaging Dimensions(3)||20x17x13cm (7.874x6.693x5.811″)|
|Inner Packing Material||Plastic Bag|
|Ancillary Packaging Materials||Styrofoam|
|Gross Weight||10.46kg (23.06lbs)|
|Transportation Carton||Carton Packaging|
|Transportation Carton Material||Corrugated Carton|
|Transportation Carton Dimensions(1)||32x28x43cm (12.60x11.02x16.93″)|
|Transportation Carton Dimensions(2)||31x21x10.5cm (12.205x8.268x4.134″)|
|Transportation Carton Dimensions(3)||20x17x13cm (7.874x6.693x5.811″)|
|Total Gross Weight of Transportation(kilogram)||10.46|
|Total Gross Weight of Transportation(pound)||23.06|
|Quantity of One Transportation Carton||3pc|