Precautions when adjusting the microscope focus
An important step in the use of the microscope is to accurately find the object when adjusting the focal length with the focusing screw. Remember not to get the following errors during operation:
1. Direct focus adjustment under high magnification lens;
2. No matter whether the lens barrel rises or falls, the eyes are always kept in the eyepiece to observe the field of view;
3. I don't know the critical value of the object distance. When the object distance is adjusted to 2cm-3cm, it is still rising, and the speed of turning the focus screw is too fast.
4. When using a low magnification lens and changing to a high magnification lens, do not turn the objective lens directly with your fingers.
It should be noted that the first two errors often cause the lens of the objective lens to contact the mount and damage the mount or lens; while the third error is a common mistake when used by beginners. When adjusting the focal length, it must be adjusted under a low magnification lens. First, turn the coarse focus screw to make the lens barrel slowly descend, so that the objective lens can slowly approach the glass slide, but at the same time, be careful not to let the objective lens touch the glass slide. During this process, pay attention to look at the objective lens from the side, and then look into the eyepiece with your left eye, and slowly reverse the adjustment of the coarse focus screw, and at the same time slowly raise the lens barrel until the object is observed. like so far. At the same time, it should be understood that the object distance of the microscope is usually kept at about 1cm, so if the object distance has far exceeded 1cm, and the object image has not been observed, it may be because the specimen is not in the field of view or the speed of the coarse focus screw is too high. Quick, at this time, you should adjust the loading position first, and then repeat the above steps, and when there is a blurred object image in the field of view, you should use the fine focus screw to adjust to further narrow the search range and improve the search range. The speed of the object image; the fourth error may cause the optical axis of the objective lens to be skewed. Because the material of the converter is soft and has high precision, the thread is not uniformly stressed, and it is easy to loosen. And once the thread is damaged, the entire converter may be eventually scrapped. Therefore, during operation, you should hold the lower rotating plate of the converter to convert the objective lens.
