Abstract

Conrady’s ‘D-d’ method for predicting the optical path difference between wavefronts in two colors is a good approximation in many cases, providing a great deal of additional information with a minimum of additional computation. However, in some optical systems, especially high numerical aperture visual systems, Conrady’s method is frequently inadequate. In such cases, exact ray tracing in several wavelengths is used to determine chromatic aberrations. Because multi-color exact ray tracing is computationally more intensive and requires more data reduction than Conrady’s method, it is desirable to restrict its use. A modified differential ray trace method is presented which expands the usefulness of the Conrady method.

© 1990 Optical Society of America