What do the field and aperture diaphragms control?

The field and aperture diaphragms play crucial roles in the optical performance of a microscope. The field diaphragm is responsible for controlling the field of view, thereby allowing the user to adjust the amount of light illuminating the specimen and reducing glare. By limiting the light to just the area of interest, it enhances contrast and detail in the images viewed under the microscope.

The aperture diaphragm, on the other hand, controls the amount of light that can enter the objective lens. It helps to focus the light onto the specimen more efficiently, which also allows for better contrast and helps to avoid the introduction of excess glare. Proper adjustment of both diaphragms results in improved image quality and optimal viewing conditions.

In combination, these diaphragms do not focus the light directly onto specimens or control brightness in a broad sense, but rather optimize the lighting conditions essential for high-quality microscopy. Thus, controlling glare and ensuring that light is focused where it is most needed directly relates to the roles of the field and aperture diaphragms in microscopy.