It is the Coarse Adjustment, but only use it on Low Power.
coarse adjustment knob
Coarse adjustment
The Coarse adjustment knob
coarse adjustment knob
Coarse adjustment moves it visibly and fine adjustment moves it only slightly
coarse adjustment knob
Coarse adjustment
it moves the stage up and down closer or further apart from the objective lenses
The function of the coarse adjustment knob on a microscope is to lower or raise the stage of the microscope. This mechanism is used to focus the specimen.
The Coarse adjustment knob
up
it moves the body tube and pbjectives up and down
coarse adjustment knob
Coarse adjustment moves it visibly and fine adjustment moves it only slightly
eyepiece diaphragm
The fine adjustment on a microscope is the smaller of the two knobs on the side. It is used after the coarse adjustment, which moves the platform up/down. It is mainly used to focus.
Course Adjustment and Fine Adjustment Knobs.