Lens instead of correction plate
The difference to the Schmidt-Cassegrain: the Maksutov has a meniscus-shaped lens on the lens aperture and no Schmidt plate. The Maksutov telescope is named after Dmitri Maksutov (1896 - 1964), a Russian optician and astronomer, who introduced this telescope design in 1941..
A telescope for planetary observing
But what are the benefits? With a uniform thickness of the lens, the system displays only slight chromatic aberration. In addition, it corrects the spherical aberration created by the primary mirror.
The system’s secondary mirror is vapour-deposited on the rear side of the meniscus lens. Therefore, there are no secondary mirror spider vanes which would bend the light. Since the secondary mirror is small, there is only a small amount of shadowing. This means: very good contrast, comparable to that of a refractor.