Under a microscope are approach screws, move the deck upward and downward. The coarse makes it fast and the micrometric slowly. They incorporate a locking knob that secures the deck to a certain height. As its name llo says macro = large... large movements...sudden... in the microscope is denoted when we move the macrometrico, and the micrometric are small movements... minimum to clarify the image, this is part of the mechanic of the microscope system.
