1. Placement of microscope: Hold the mirror arm with the right hand, hold the mirror base with the left hand, place the microscope on the experimental table, slightly to the left, about 7 cm from the edge, and place the eyepiece and objective lens.

1. Turn the converter so that the low-power objective lens is aligned with the light hole, and the front end of the objective lens should keep a distance of 2 cm from the objective table.
2. Aim a larger aperture at the light hole. Look at the eyepiece with the left eye, open the right eye, and turn the reflector to make the light reflect into the lens barrel through the light hole. Until you see a brighter field of vision.

1. Place the specimen of the slide to be observed on the stage, and hold it down with a tabletting clamp, with the specimen facing the center of the light hole.

1. Turn the coarse quasi-focus screw to slowly lower the lens barrel, and watch from the side until the objective lens approaches the slide specimen, so as to avoid the objective lens touching the slide specimen.
2. Look into the eyepiece with the left eye, and turn the coarse quasi-focus screw in the opposite direction at the same time, so that the lens barrel rises slowly and straightly.
Until you can see the image clearly. Then turn the fine quasi-focus screw slightly to make the object image more clear.

1. Go to the next slice
2. Turn the converter so that the place with low magnification objective lens or no objective lens is aligned with the light hole, lower the lens barrel and approach the objective table.
3, the mirror stand.

The resolution of microscope refers to the minimum distance between two objects that can be clearly distinguished by microscope, also known as "discrimination rate". The calculation formula is σ=λ/NA, where σ is the minimum resolution distance; λ is the wavelength of light; NA is the numerical aperture of the objective lens. It can be seen that the resolution of the objective lens is determined by the NA value of the objective lens and the wavelength of the illumination source. The larger the NA value, the shorter the wavelength of illumination light, and the smaller the σ value, the higher the resolution. To improve the resolution, that is, to reduce the σ value, the following measures can be taken:

(1) Reduce the wavelength λ value and use a short wavelength light source.

(2) Increase the N value of the medium to increase the NA value (NA=nsinu/2).

(3) increase the aperture angle u to improve the NA value.

(4) increase the contrast between light and shade.