Martin S. answered • 03/29/20
Patient, Relaxed PhD Molecular Biologist for Science and Math Tutoring
If you mean a compound microscope, the kind that uses visible light, then it is by aligning two concave lenses over an object and bringing the two lenses into focus relative to each other. Each lens has a certain magnification value, and the total magnification is determined by multiplying the two values. The eyepiece is typically 10X, and most microscopes used in schools have the lenses at the bottom of the tube, 4X, 10X, 40X. With that type of microscope the total magnification would be 40X, 100X, or 400X depending on which lens was selected at the bottom.
Electron and positron microscopes work differently and have much higher magnification. Those work by aiming a beam of electrons or positrons at an object and a sensor determines how the beam was scattered
