Where is diaphragm of microscope located to regulate the amount of light shown?

The diaphragm of a microscope is typically located beneath the stage, between the light source and the specimen being observed. It consists of an adjustable opening that controls the amount of light entering the optical path. By altering the diaphragm's aperture size, users can enhance contrast and improve the visibility of the specimen. This feature is crucial for achieving optimal illumination in microscopy.