Optical Design with the Schmidt Concept: 1) Ground-Based Development: 2) The Space Schmidt Project for the 1990's ?

Abstract

The basic principle of the camera described by Bernard Schmidt in 1932 is that a single concave mirror with a stop at its center of curvature has no unique axis and therefore yields equally good images at all points of its yield. The field is curved, and to correct the spherical aberration produced by the mirror, Schmidt introduced, in the stop at the center of curvature of the mirror, a thin non spherical corrector plate of glass. Around 1930 at the Hamburg Observatory and in spite of many difficulties, it was Schmidt's genius as an optician that succeeded - after several judiciously interpreted trials - in figuring a corrector plate by elastic relaxation, and thus demonstrated the optical performance of this new generation of instruments.