chapter  18
10 Pages

Optics

WithMatthew D. McCluskey

A lens is typically made of glass or plastic and has one or two curved surfaces that refract light. The curvature is designed so that parallel light rays all converge at a focal point (f); see Figure 18.1. Rays that emanate from f will be made parallel. A light ray that passes through the center of a thin lens does not change its direction.