## The Automatic Lens-Design Program

We can make a lens out of many materials and in many ways. We can vary the curvature of each surface and the distance between the surfaces. Each surface may be flat, spherical, parabolic, elliptical, hyperbolic, or some other form. A camera lens usually consists of several optical elements. The elements may be cemented together in close contact or separated by any distance.

No one knows the best design for any given application. Lens design is very complicated. When a new instrument needed a lens, members of the Optical Physics Group took charge of its design. They chose among known lens designs the one that seemed best for the application. Then they entered the design parameters in a computer. The program had all the mathematical formulas pertinent to lens design.

The program was a jealously guarded company secret. It had a pretentious name, “Automatic Lens Design.” A programmer was in charge of keeping the program up to date with all improvements in lens design.

The program traced light rays through the lens using mathematical formulas incorporated in the program, and sought the focal point of the image. The usual result was that not all of the rays focused on the same point. This design fault is called “aberration.” Lens designers have classified six aberrations that constantly plague their lenses.

No one knows the best design for any given application. Lens design is very complicated. When a new instrument needed a lens, members of the Optical Physics Group took charge of its design. They chose among known lens designs the one that seemed best for the application. Then they entered the design parameters in a computer. The program had all the mathematical formulas pertinent to lens design.

The program was a jealously guarded company secret. It had a pretentious name, “Automatic Lens Design.” A programmer was in charge of keeping the program up to date with all improvements in lens design.

The program traced light rays through the lens using mathematical formulas incorporated in the program, and sought the focal point of the image. The usual result was that not all of the rays focused on the same point. This design fault is called “aberration.” Lens designers have classified six aberrations that constantly plague their lenses.