US Patent 7595942 Light collimating system for schmidt-cassegrain telescope

Disclosed is a light collimating system for mounting at the primary focus of a Schmidt-Cassegrain telescope (SCT) in place of the secondary mirror. The system comprises a housing containing a plurality of lens elements optimized to reduce optical aberrations. The resulting system has a focal ratio of approximately f/2, a short exposure time for optical imaging, and a wide field of view with very little distortion. The housing is attached to the corrector plate of the SCT by a pair of rings held together by a plurality of screws that further facilitate the alignment and rotation of the light collimating system.