The RC (Ritchey–Chrétien) telescope, a brainchild of George Ritchey and Henri Chrétien in 1910, stands as a specialized iteration within the Cassegrain optical system. Named after its inventors, this telescope design boasts a primary hyperbolic mirror and a secondary hyperbolic mirror, meticulously engineered to eradicate off-axis optical errors like coma. Notably, the RC Telescope distinguishes itself with its broader field of view and minimized optical aberrations compared to conventional reflecting telescopes. Its inherent elimination of chromatic aberration also positions it favorably against refracting telescopes. The majority of astronomical telescopes lean towards reflective designs owing to their capacity to capture a wide range of wavelengths, facilitated by metal coatings.
Evolution of Reflective Telescopes
Reflective telescopes, spearheaded by Newton’s pioneering efforts with a spherical mirror, have a long history. However, the inherent spherical aberration in such mirrors, coupled with limitations in aperture size, imposes constraints on both focal ratios and image quality. While spherical mirrors offer rotational symmetry conducive to uniform image quality across the field of view, they are best suited for systems with modest aperture and quality demands. The spherical aberration issue prompted optical designers to explore innovations, giving rise to variants such as the Cassegrain system.
