Catadioptric Telescopes

Abstract

While the invention of the refractor and reflector occurred within roughly half a century of each other, there was no new form of astronomical telescope to appear on the scene for nearly another three centuries. The idea then dawned on telescope designers/makers of combining the attributes of both the refractor and the reflector into a single system, which became known as the catadioptric (or compound) telescope. In 1930 Bernhard Schmidt used a thin aspheric corrector plate on a fast Newtonian reflector to flatten and sharpen the field for wide-angle photography, giving birth to the Schmidt camera. Then a decade later, Dimitri Maksutov combined a thick meniscus lens with a Cassegrain reflector to greatly improve both visual and photographic performance, resulting in the Maksutov-Cassegrain.