In addition to the common 1X interface, the C-type interface adapter for microscopes also offers two options: 0.35X, 0.5X, and 0.63X. So what is the difference between these three adapters? In fact, the choice of adapter is related to an important parameter of the microscope - the field of view.
Field of view (FN) is the diameter (mm) of the field of view that can be observed through the eyepiece. The diameter of the circular area where a specimen can be observed under a microscope is called the actual field of view.