Paul L. Ruben

Refractive null correctors for aspheric surfaces.

The usefulness of a refractive null corrector is limited by how closely its aberrated wavefront can match the aspheric surface that requires testing. Guidance in both the design of the asphere to insure its nullability and the design of the null corrector is presented. A functional and constructional compendium of null corrector designs is proffered.

Design and use of mass-produced aspheres at Kodak

Aspheric surfaces provide both performance and cost advantages for large-quantity lens production. Aspheres are reviewed from their early application in viewfinders to their use in camera lenses and, most recently, to applications in laser focusing lenses. There are restrictions imposed on the shape or strength of aspheres by either the manufacturing processes or testing techniques that the designer must recognize.

A cost-aperture study of a family of lenses.

A series of five lenses ranging in aperture from f/1.0 to f/1.6 were designed with the aid of a large computer. A search was made for the least complex lens that would yield a given level of optical performance in an effort to optimize manufacturing costs with relation to lens speed for a family of lenses. Such a relationship was established.