Abstract

Various null-testing arrangements have been used over the years, for testing concave non-spherical mirrors. We have researched a method for null testing which uses a single plano-convex lens to compensate for the spherical aberration of a concave mirror, when tested at its center of curvature. This testing method, called the Ross test, requires a high-quality null lens and a standard Foucault tester. In this article, we present graphical and numerical data which provides the necessary parameters for implementing the Ross null test, for mirrors having focal ratios ranging from f/3.5 to f/10.0, and for conic deformations ranging from eccentricities of 0.70 to 1.50.

© 1990 Optical Society of America