How to Adjust the Microscope to Make Objects Clear
Microscopes have been widely used in modern science.
The types of microscopes are divided into optical microscopes and electron microscopes according to the broad categories.
Optical microscopes can be divided into transmission type and reflection type according to the difference of optical path form;
Electron microscopes can be divided into transmission type and electronic scanning type. The difference from optical microscopes is that the resolution is greatly enhanced. However, samples are generally required to be placed in a vacuum chamber, and some samples are not suitable.
Here we take the common reflective optical microscope as an example to illustrate the adjustment imaging method, and the principle of the transmissive optical microscope is the same.
The optical microscope mainly uses the objective lens group and the eyepiece lens to form an image, and the objective lens and the eyepiece lens are usually equipped with lens groups with different magnifications. Through combination, a very large magnification range can be formed. This configuration is because although the details of the high-magnification lens group are clearly displayed, the field of view and depth of field are narrow, and it is not convenient to move in different target areas. Although the magnification of the low-power lens group is small, the field of view and depth of field are large, which is convenient for searching targets in a wide range. In addition, some specific samples do not require a large magnification, but all objects in the field of view are required to be as clear as possible, so the low-magnification lens group is also useful. The combination of the two can obtain perfect clear imaging.
1. Required materials and tools:
Objective lens group: such as 100x, 200x, 300x, 600x, etc.
Eyepiece group: such as 5x, 10x, 15x, 20x, etc.
Focusing handwheel: including coarse adjustment and fine adjustment
Stage: can move in any direction in a plane, easy to find the target area
sample
light source
color filter
2. Step method:
Turn on the light source
Rotate the coarse adjustment handwheel to separate the objective lens group from the stage to a safe distance
According to experience, change to low power objective lens group and suitable eyepiece group
Place the necessary processed samples on the stage
Adjust eyepiece interpupillary distance
Move the sample through the stage, search the sample and the target area, observe and select the target through the coarse adjustment handwheel
Replace the appropriate high-magnification objective lens and eyepiece, and focus carefully by fine-tuning the handwheel
Research can be carried out as soon as a clear image is obtained, taking pictures if necessary
After finishing the work, turn off the light source and remove the sample. The objective lens group and eyepiece group must also be removed and stored in a dedicated dry and cool place, such as a drying bottle.
2. Matters needing attention:
Focusing skills: When fine-tuning the focus, there must be a blur-clear-re-blur process, the purpose is to confirm the most accurate focus point found, so you need to go a little bit, and then return to the clear focus position.
For samples of certain shapes, color filters can be selected to improve the clarity of details. For example, for substances sensitive to narrow wavelengths and fluorescently stained samples, a color filter of a specific color can be inserted in the optical path. In addition, in order to observe special structures in metal samples, polarizers can be inserted, the angle can be adjusted, and the state of the structures can be studied by observing the specific polarized light reflected by them.
