WideFastCam
WideFastCam
The effective focal ratio of the primary mirror is f/2.8, and the unvignetted field of view is 40 arcminutes. When not operating at prime focus, a convex hyperboloidal secondary mirror, made of Zerodur, 1.0 m in diameter, directs the light through a central hole in the primary mirror to the main instrumentation mounted at the Cassegrain focus beneath the primary mirror cell.