How to distinguish high magnification objective lens from low magnification objective lens
1. Generally, the lens will be marked with a multiple;
2. Generally, the high-power objective lens is long and the low-power objective lens is short;
3. It can be identified by the color circle: 4 times red, 10 times yellow, 40 times blue, 100 times white;
4. The low-magnification objective lens has a bright field of view, while the high-magnification objective lens has a small dark field field.
After the magnification of the microscope is increased, the number of cells in the field of view increases from large to small, and the cell volume increases from small to large. The greater the magnification, the smaller the light transmission diameter of the lens, and less light passes through, so the field of view becomes darker.
The imaging principle of microscope:
Light → Reflector → Shutter → Clear aperture → Transparent specimen → Objective lens (magnified into an inverted real image) → Lens tube → Eyepiece (magnified into a virtual image) → Eye
Special reminder: The most important parts of a microscope are the objective lens and eyepiece. When observing specimens, the eyepiece, objective lens, aperture, and aperture must be in a straight line.
Common mistakes:
It is mistakenly believed that the greater the magnification of the microscope, the more cells can be seen in the field of view:
The size of the field of view of the microscope remains unchanged. If the magnification is increased, the size of the cells seen in the field of view will increase, and the cells at the edge of the original field of view will be outside the field of view, and the number of cells must be less than before.
When the microscope field of view is too dark, how to adjust the microscope to improve the brightness of the field of view
There are two methods: changing to a larger aperture and using a concave mirror to reflect light
1. Change to a larger aperture
There are large and small apertures on the shutter. Use the small aperture when the light is strong, and use the large aperture when the light is weak. Use a wide aperture to let in more light and make the light brighter.
2. Use concave mirror for reflection
The reflector has two sides: a plane mirror and a concave mirror. When the light is strong, a plane mirror is used, and when the light is weak, a concave mirror is used. Therefore, when the outside light is dark, in order not to affect the observation effect, a concave mirror should be used.
