Conic constant trade-off study in Cassegrain type telescopes with afield corrector

摘要

The fabrication and optical performance of a Cassegrain type telescope that employs a field corrector depends on the conic constant of the primary mirror. The design of the field corrector calls for different choices on mirror asphericity which imply a departure from the nominal Cassegrain or Ritchey-Chre'tien solutions. This departure may not be acceptable given that the telescope would not operate properly without the field corrector. In this paper we present a study of the variation of mirror conic constant and field corrector choice of some existing telescopes. We also discuss some trade-offs in the design of a telescope with a field corrector.