Condenser (microscope)

A condenser consisting of one or two condenser lenses, and is used in the illumination device of an imaging optical device. Such working with lamplight devices are projectors ( slide projector or enlarger ) or microscopes. The condenser 's job to bring in as much of the light from the projection lamp in the imaging beam path. It should also ensure that the image is uniformly illuminated.

Often with condenser already the entire lighting system meant.

The condenser is the filament of the lamp into the aperture of the imaging lens, so that instead of the coil whose magnified image to the entrance pupil of the lens and a greater brightness occurs.

It is mounted just in front of the object to be imaged. So he will continue field lens (especially as field lenses are generally located at the site of an intermediate image ) that does not affect the image of the object, but improves the image brightness.

The lighting system consists of condenser / n and lamp and usually more of a spherical mirror, whereby the one involved in the projection amount of light is approximately doubled. This often involves even a heat protection filter, which is located at the condenser bipartite between the two lenses.

To save length, the condenser is often built with a large opening angle ( large numerical aperture ). This requires so-called spherical aberration, which can lead for example to uneven illumination of the image. It improves the situation by distributing the imaging function of the condenser to more appropriately corrected lenses. The double condenser then contains an aspherical and a spherical converging lens.