The difference between biological microscope and metallographic microscope is mainly in the illumination mode and objective lens:

1. Biological microscopes use transmitted illumination, which is generally used to observe transparent and translucent samples. It cannot be used to observe opaque objects. Metallographic microscopes mainly use epi-illumination. The light source is emitted from the objective lens and is mainly used to observe opaque samples. Of course, there are also advanced metallurgical microscopes with transmitted illumination devices, which can be used to observe transparent samples at the same time.

2. From the perspective of the objective lens, the high magnification objective lens of the biological microscope considers the thickness of the cover glass (0.17) and the thickness of the glass slide and the culture vessel (1.2), so the objective lens is usually marked with /0.17 (upright microscope), / 1.2 (Inverted microscope), the objective lens of an upright biological microscope below 10 times is /-, which means it can be ignored. This is to correct the influence of glass on light refraction, and the objective lens of a metallurgical microscope is usually marked with /0.

　　 The difference between biological microscope and stereo microscope and metallographic microscope. Stereo microscope is also called stereo microscope. The main differences from biological microscope are as follows:

　　 1. The working distance of a stereo microscope is relatively large, which can usually reach 50mm or even 150mm; while the working distance of a biological microscope rarely exceeds 20mm.

　　 2. Stereo microscopes can place taller and thicker objects, such as integrated circuits, larger workpieces, screws, thicker objects, etc., while biological microscopes can only place thin slices, glass slides, etc.

　　 3. Stereo microscope has a large depth of field, up to a depth of 10mm. Adjust the focus ring, and a clear image can be seen in a relatively large range; while a biological microscope may turn the focus ring a little bit and it will be difficult to see.

　　 Fourth, a stereo microscope can see three-dimensional images because of the wide range of depth of field. However, the magnification is small, and the maximum magnification of the general stereo microscope is about 200 times; the maximum magnification of the biological microscope is generally about 2000 times, and the characteristic parameters of the biological microscope are just opposite to the stereo microscope. Therefore, the scope of adaptation of a stereo microscope and a biological microscope is different, and the lens structure is also different.