On the conversion of lens aperture

There is such a special device called an adapter, which is very simple to use. The eyepiece of an ordinary microscope is detachable. Just connect one end of the adapter to the eyepiece and the other end to the lens bayonet of the SLR camera.

It seems that it was sold in the Golden Elephant Pharmacy under Huawei Building in Xidan a few years ago, but I don't know if it is available now. You can go and have a look.

About the scientific name: his specific scientific name is different. Some places are called adapters, and Beijing should be called adapters (unofficial name, I don't know the official name). Some manufacturers of microscopes and cameras should be able to buy them, but I'm not sure where to buy them in Beijing now. Try your luck in Wukesong Photographic Equipment City. There should be a larger medical equipment store to order.