Maksutov-Cassegrain Telescopes

Maksutov-Cassegrain telescopes are similar to Schmidt-Cassegrains, using both mirrors and a lens to focus light into a smaller area. Maksutov-Cassegrains replace the familiar corrector plate and secondary mirror of the Schmidt-Cassegrain with a convex meniscus lens. The secondary mirror is actually a silvered spot on the inside of the meniscus lens. This in itself leads to one major advantage: Maksutovs do not require periodic collimation of the optics as do Schmidt-Cassegrains and Newtonians.

Maksutov-Cassegrains offer superior contrast to a Schmidt-Cassegrain due to the smaller central obstruction of the secondary mirror. They are suitable for both astronomical and terrestrial observing due to the upright image they produce, and are an excellent choice for planetary and double star observing. The only noteworthy disadvantage to a Maksutov-Cassegrain is the relatively slow focal ratio that results in a narrow field of view in comparison to other optical designs with similar aperture.