Diaphragm meaning

There are two things that must happen for a microscope to work successfully. One, the light must hit the specimen we want to see, and two, after hitting the specimen, the light needs to get collected and magnified. The diaphragm and condenser are important components of this first mechanism, in focusing the incoming light. The microscope diaphragm, also known as the iris diaphragm, controls the amount and shape of the light that travels through the condenser lens and eventually passes through the specimen by expanding and contracting the diaphragm blades that resemble the iris of an eye. Depending on the type of diaphragm and the settings applied to the diaphragm this can have minute but important effects on the quality of the image. In this post I will take you through all the nuances you need to know that will improve your microscope observations and ensure you get the best quality images given the equipment you possess. Function and Purpose The primary function of the diaphragm is to change the angular aperture of the cone of light that is produced after the light travels through the condenser. The size of this cone of light is important because if there is a mismatch between the size of the cone of light and the optimal numerical aperture on the objective lens in place you will not get the optimal image quality. On the left, we have a generic light source. The two lenses to the right of the light source are the condenser. The first lens converges the incoming light and...