What is the purpose of having 2 focus adjustments on a micro

What is the purpose of having 2 focus adjustments on a microscope?

Solution

Answer:

One is coarse focus and other one is fine focus adjustment knob. The coarse knob moves the eyepiece up and down quickly, to get the thingy you’re trying to look at roughly (in focus), it makes easy to focus the specimen at lower magnifications. The fine adjustment knob changes focus slowly and makes it easier to really fine-tune the focusing at the higher magnifications.