CELESTRON Reducer Corrector F6.3 #94175Explicitly designed for Celestron Schmidt Cassegrain telescopes, this unique lens reduces your telescopes focal length and f ratio by 37%, turning your long focal length telescope into a fast, short focal length instrument. A f 10 focal ratio now achieves a f 6. 3, while an f 11 focal ratio now achieves a f 7. For visual use, this means you get lower power with the same eyepiece and a wider field of view. Photographically you also get a wider field