TABLE OF CONTENTS In the immediately preceding chapters, we have been concerned with the analysis of optical systems, in the sense that the constructional parameters of the system were given and our object was the determination of the resultant performance characteristics. In this chapter we take up the synthesis of optical systems; here the desired performance is given and the constructional parameters are to be determined. A large part of the synthesis process is, of course, concerned with analysis, since optical design is in great measure a systematic application of the cut-and-try process.
There is absolutely no "direct" method of optical design for original systems; that is, there is no sure procedure that will lead (without foreknowledge) from a set of performance specifications to a suitable design. However, when it is known that a certain type of design or configuration is capable of meeting a given performance level, it is a fairly straightforward process for a competent designer to produce a design of the required type. Further, modest improvements to existing designs can almost always be effected by well-established techniques. Thus, it is apparent that a good portion of the ammunition in a lens designer's arsenal consists of an intimate and detailed knowledge of a wide range of designs, their characteristics, limitations, idiosyncrasies, and potentials. Here is one part of the art in optical design; basically it consists of the choice of the point at which the designer begins.
The electronic computer, in the course of little more than...
