Schmidt–Cassegrain
Also called: SCT, catadioptric.
A compact telescope with a mirror and a front corrector plate; long focal length (f/10) in a short tube.
SCTs fold a long light path into a short tube, so an 8-inch is portable and a 14-inch fits on a mount. Their long focal length gives high power easily — great for planets and small objects — but narrow fields; an f/6.3 focal reducer widens them. They often come on computerised GoTo mounts.