title: Compound catadioptric telescopes with all spherical surfaces.
abstract: Catadioptric, all spherical Cassegrainian and Gregorian telescopes with one and two full aperture corrector lenses are investigated. Appropriate closed form third-order aberration equations are presented, and a variety of aplanatic and anastigmatic solutions are indicated.
authors.forename: R D
authors.initials: RD
authors.lastname: Sigler