1) Astronomical instrument
Found on
https://www.crosswordclues.com/clue/telecompressor
A telecompressor or focal reducer is an optical element which amateur astronomers use to reduce the focal length of a telescope. Such devices are also available to photographers, for using lenses between systems with different sensor sizes. Mainly used for astrophotography, the telecompressor gives a wider angle of view, a sharper picture, and red...
Found on
http://en.wikipedia.org/wiki/Telecompressor
No exact match found.
