Feature

The Changing Nature Of Lens Design

R. R. Shannon

Lens design is fundamental to the development of most modern optical technology. Efforts to understand the way in which lenses work led to new designs that were realized as commercial successes and provided the resources to develop new methods for design. Aberration theory developed as the foundation upon which lens designs were created. The exact analysis of images by tracing a number of rays was too tedious in the first third of this century, as the only approach to ray tracing was the use of logarithmic tables and handwritten calculations. Each designer had to squeeze the maximum information about the lens from each ray traced. Tracing a meridional ray might proceed at about a ray surface per 15 or 20 minutes, and skew rays were hardly ever traced at all.