What does the coarse adjustment on a microscope do?
The coarse focus adjustment moves the lens (or the stage, depending on the construction of the microscope). So does the fine adjustment but the fine does it much less and much more accurately (less play in the gears)
There are two adjustment knobs (coarse and fine) on a microscope so you can move the stage at two different speeds. The coarse moves a lot per revolution, while the fine adjustment knob moves the stage at such small increments that it is nearly impossible to notice when looking from the side. The coarse adjustment knob should be used to get the stage closer to the lens only while you are looking at the microscope…
I'm pretty sure fine adjustment. But coarse adjustment also works. The power doesn't matter, There is ONE difference. Coarse adjustment- A knob that focuses the microscope on the specimen by RAISING and LOWERING the body tube of the scope. Fine adjustment- A knob that adjusts the HEIGHT of the body tube.