Telecompressor

A telephoto compressor, often Wide-converter or Brennweitenreduzierer, English Telecompressor or focal reducer called, is an optical accessory for camera lenses with the opposite effect of a teleconverter. He looks similar to a teleconverter and is also mounted between the lens and camera. It reduces the focal length of a lens by a specified factor, at the same time, the speed of the lens is increased by this factor and the exposure times are reduced accordingly.

Use

Tele compressors are mostly used in amateur astronomy in order to customize with telescopes still photographs situated closer to or larger objects than would be possible without tele compressor. But in general photography Tele compressors are used. It is important to note that the lens must illuminate a larger image circle than would be necessary for the film or sensor format because the image circle is reduced by the tele compressor. It would be possible, for example, the use of a lens for the small picture format to a camera with a sensor in APS -C format.

The early digital cameras E2 and E3 Nikon used a built- Tele compressor, so that F lenses could be used without the inclusion of a size factor with the small 2/3 " sensor of the camera. Thereby the lowest ASA value of the camera is increased on for the time unusual 800

Also tele compressors are also provided for some mirrorless system cameras that allow the adaptation of small -screen lenses on their smaller sensors.