How Do I Choose the Best Amateur Telescope?

The Ritchey-Chrétien telescope (RCT) is a professional Cassegrain telescope. It is designed to eliminate coma aberrations. Compared with conventional configurations, it can provide a larger field of view. . The primary and secondary mirrors of the RCT are hyperbolic mirrors, invented by the American astronomer George Willis Ritchey and the French astronomer Henri Chrétien in the early 1910s. . Ritchie first built a 0.5-meter RCT in 1927, and the second was a one-meter RCT made by Ritchie at the United States Naval Observatory.