Astrophotography
From The Glossary of Digital Photography
The photography of stars, planets, comets, galaxies, and other astronomical objects, usually with a camera mounted on a telescope. Most professional astrophotography has converted from film to digital capture techniques because of the greater sensitivity possible. In the past, extremely long exposures were required with film. With long exposure came the need for special tracking equipment so that the telescope could slowly rotate and follow the object being photographed. This is often not the case with digital. Digital imaging does require special post-processing techniques to reach its full potential. Some of these techniques include processing to remove light pollution and using a dark frame capture to remove noise caused by thermal issues. In some cases, the CCD is cooled to reduce thermal noise.
