The Ritchey-Chrétien is a Cassegrain-type telescope design that uses hyperbolic primary and secondary mirrors to provide images that are free from spherical aberration and coma over a very wide field.

Because of its wide field and relatively fast focal ratio (often f/8 or faster), the RC design is better suited to wide field astrophotography and visual observing than optically slower classical Cassegrain, Schmidt-Cassegrain, and Maksutov-Cassegrain optical designs.

Many professional reflector telescopes in the world's observatories are Ritchey-Chrétiens, including the twin 10-meter Keck telescopes in Hawaii and the Hubble Space Telescope.

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