Practical Optical System Layout is intended to help the reader who is undertaking the design of an optical system answer the question, What do you do when the paper is blank? This question is often cited by my friend and colleague Max Riedl, who, being of a very orderly and systematic turn of mind, usually proposes as a partial answer, First you draw the centerline. (Were he more optically and less mechanically inclined, I suspect he might say optical axis rather than centerline. ) But behind these slightly cryptic sentences is the implication that every optical system design must begin on a very basic level. The design proceeds from the centerline in orderly steps, by first determining what components are necessary to meet the system requirements. Then the powers of the components and their locations are determined, allowing for any requirements such as clearances, system folds, or packaging constraints. This is optical system layout, and it is the primary topic of this book.

The optical layout process, that is, the choosing of the powers and spacings of the components which make up the optical system, may seem like a trivial thing, since the layout can be completely described in very simple terms, and its development requires only the use of paraxial optics. It is, nonetheless, an extremely important part of the process of developing an optical system, and the simple paraxial layout may play a leading role in determining the cost, complexity, sensitivity, robustness, and performance of the finished system.