The Vixen Optics VC200L Reflector Telescope with Dual Speed Focuser is a catadioptric telescope with a unique and elaborate aspherical optical design that distinguishes it from standard Cassegrains. VISAC stand's for Vixen Optics's Six-Order Aspherical Cassegrain and is a highly specialized telescope designed for astro imaging.
It has been engineered with a high precision sixth order aspherical primary mirror, a convex secondary mirror and triplet corrector lens. A retaining ring instead of the more main-stream hooks holds the primary mirror in place. The result of all these revolutionary design features is to decrease flare, enhance contrast, achieve superior image correction and deliver precise pin-dot stars to the very edge of the field of view.
Stars are sharp even at the edge of the 35mm film format of the larger CCD chips. This telescope does not impose a limitation on the quality of astrophotography. Many optics claim aberration free photographic fields with perfectly corrected coma and curvature - the VC200L permits it.