what is the function of the diaphragm in a microscope

 

 

 

A diaphragm on a microscope is the piece that enables the user to adjust the amount of light that is focused under the specimen being observed. A diaphragm is typically found on higher-power microscopes versus less expensive or toy models. The diaphragm is located directly under the stage or platform where user places the specimen or slide. The diaphragm disc, sometimes called an iris, has tiny holes in it that let varying degrees of light in under the specimen. By opening the diaphragm, an item that at first appears too dark is easier to observe. Adjusting the diaphragm can also create contrast for better viewing transparent specimens.

 

 

A diaphragm on a microscope is the piece that enables the user to adjust the amount of light that is focused under the specimen being observed. A diaphragm is typically found on higher-power microscopes versus less expensive or toy models. Diaphragm – often called aperture – is part of beam or image control system. It’s aim is to improve beam shape (in condenser system) or image contrast (in objective system).The diaphragm or Iris’ location is under the stage of the microscope and above it is the condenser.This apparatus’ function is to control the amount of light that is allowed to pass through the specimen being viewed.Most quality microscopes have an Abbe condenser with an Iris diaphragm. They work together to focus and control quantity of light.

 

 

Physically diaphragm is a metal or plastic strip with number of holes in it – each hole have a specific diameter.In condenser (beam) system size of the diaphragm sets the illumination intensity and convergence angle.In objective (image) system the diaphragm “screens” parts of the beam that are not needed for this specific image and this way improves the image contrast.