Corrector plates for Schmidt-Cassegrain systems are subjected to equivalent focal length changes if the neutral zone varies from the established 0.86 zone. Fabricating a plano-convex element first, before changing to a corrector plate (C .P.) removes almost 50% slope departure. Shifting of the neutral zone is caused by the non-control of the grinding with glass tool rings. The control of the neutral zone can be accomplished by other fabrication methods.

Date Published: 9 December 1983
PDF: 2 pages
Proc. SPIE 0433, Contemporary Methods of Optical Manufacturing and Testing, (9 December 1983); doi: 10.1117/12.936808

Published in SPIE Proceedings Vol. 0433:
Contemporary Methods of Optical Manufacturing and Testing
Gregory M. Sanger, Editor(s)