Finite. Total Magnification: 40-400X. 10X Eyepiece. 4X 10X 40X Achromatic Objective. Inverted. Eye Tube Angle: 45°. Eyepiece Field of View: Dia. 18mm. Illumination Type: LED Coaxial Transmitted Light.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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.
|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|
|BM09032211 (10X Dia. 18mm)|
|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.|
|Desiccant Bag||1 Bag|
|Product Instructions/Operation Manual||1pc|
|Packaging Type||Carton Packaging|
|Packaging Material||Corrugated Carton|
|Packaging Dimensions(1)||24x24x8cm (9.449x9.449x3.150″)|
|Inner Packing Material||Plastic Bag|
|Ancillary Packaging Materials||Expanded Polystyrene|
|Gross Weight||1.30kg (2.866lbs)|
|Transportation Carton||Carton Packaging|
|Transportation Carton Material||Corrugated Carton|
|Transportation Carton Dimensions(1)||24x24x8cm (9.449x9.449x3.150″)|
|Total Gross Weight of Transportation(kilogram)||1.30|
|Total Gross Weight of Transportation(pound)||2.866|
|Quantity of One Transportation Carton||1pc|