The Optical Microscope (draft)

Introduction The optical components of a microscope are its two imaging lenses (eyepiece and objective) and a condenser lens. The eyepiece and objective are responsible for magnifying the image of the specimen and projecting it onto the viewer’s retina or onto the film plane in a camera. The job of the condenser lens is to focus a cone of incident light onto the specimen. To provide the incident light there is an illumination system which may include the source of the incident light or may direct external natural or artificial light towards the condenser lens. It can also provide means for enhancing the contrast and detail seen in the image. Finally, there is a movable stage which holds the specimen in the optical path and allows the specimen to be moved in and out of the focal plane and even left, right and rotated about the optic axis. To complete the instrument the microscope may include other attachments: cameras, a viewing screen, even hot and cold stages.