The Systematic Design of Two-component Objectives

Abstract

A self-contained account is given of systematic methods for the preliminary design of corrected two-component objectives, employing design parameters which remain valid in all cases. Explicit formulae given the necessary values of spherical aberration and central coma for each component in useful forms. A simple algorithm is described with which glass types and lens shapes may be determined to give the desired primary aberrations; and a second algorithm is used which permits zero-thickness elements to be replaced by ones of finite thickness, and other design changes to be made to a given component, without disturbing the detailed Gaussian optics of the complete system and also leaving exactly unchanged the primary aberrations of the remaining components. The methods are suitable for use with electronic desk computers having limited storage and programming capabilities. The two algorithms described are applicable to the whole range of optical design problems, and are of particular advantage in the preliminary design stages of zoom lenses.