fine adjustment knob
Nosepiece
focus
The small knob is called the fine focus knob, and the big knob is called the coarse focus knob on a microscope. The fine focus knob is used for precise focusing, while the coarse focus knob is used for initial focusing.
The large knob on the side of a microscope is used for coarse focusing, which moves the objective lens closer or farther from the specimen in larger increments. The small knob is for fine focusing, which allows for precise adjustments to bring the specimen into clear focus.
The fine adjustment knob on a microscope is typically located on one side of the base near the coarse adjustment knob. It is used to make precise focusing adjustments when viewing a specimen under high magnification.
the coarse adjustment knob
Fine focus knob is used to make small adjustments on a microscope for sharp focusing.
the right side
The focus adjustment knob is located on the side of the frame to adjust the focus of the microscope. By turning this knob, you can move the stage up and down to bring the specimen into focus.
it is the COURSE adjustment knob
This is the coarse adjustment knob. This should be used before the fine adjustment knob (the smaller knob) - which is for fine focusing.
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 from the side. The fine adjustment knob can be used when you are looking into the microscope because there is a much lower chance of running the stage into the lens and breaking it.