Spherical fits to an aspheric surface provide a measure of the raw asphericity, give an easily generated starting point for its fabrication, and show the amount of aberration to be expected in a center of curvature test. Conicoidal fits have similar uses. We have previously shown that a conicoidal fit can be substantially closer than a spherical fit. In this paper we include fits to sections of plane symmetric surfaces that have no symmetry and give examples of such fits to surfaces of a completely asymmetric lens.
© 1989 Optical Society of America
Berge Tatian, "Least-squares fitting of aspheric surfaces by a conicoid," Appl. Opt. 28, 4687-4696 (1989)