Catadioptric
A third group of telescopes, called catadioptrics, are hybrids of the refractors and reflectors. A catadioptric,
which means mirror-lens, uses a combination of both mirrors and lenses to manipulate and focus the light rays.
Examples of these are the Catadioptric-Newtonian, the Schmidt-Cassegrain, the Maksutov-Cassegrain and the
Houghton-Cassegrain telescope.