Maksutov Cassegrains
High contrast telescopes.
Maksutov-Cassegrains are very similar to Schmidt-Cassegrains, but they use convex meniscus lenses instead of corrector plates. The main advantage here, compared to other similar models is that Maksutov-Cassegrains don’t need periodic collimation as many other telescopic models do. In addition, because mirror obstruction is smaller, images appear with greater contrasts, but will have a narrower field of view due to the Maksutov-Cassegrain’s slow focal ratio which tends to make this telescope design better for planetary and double star observing.