Friday, April 06, 2007

A Microscope Condenser consists of a lens or set of lenses that focuses the light onto the specimen. There are different types of condensers, such as a condenser incorporated in the stage, and a condenser that is incorporated under the stage and is able to focus light. In most condensers, the top lens can be unscrewed from the field lens, which can itself be unscrewed and removed from the mount with diaphragm. The lenses can safely be cleaned by slightly breathing on the lens surface and wiping the surface firmly with a tissue. Dusty condenser lenses have little effect upon image quality except for dry darkfield setups where dust on the top lens will catch the light and cause flare in the black background. Scratches on the top lens will have the same effect. The Microscope Condenser plays a critical role in image formation. Highly corrected condensers are complex and are made of a number of lenses. Like a microscope objective, a microscope condenser has a numerical aperture and it should equal or better be of the highest magnification objective being used.