Abstract: An optical system for scanning a light beam on a flat field surface includes a source of a diverging light beam, a scanner for redirecting the light beam over the surface of the flat field and a single converging meniscus lens disposed in the optical path between the scanner and the flat field surface for focusing the diverging light beam as a point at all locations on the flat field. The diverging light beam which may be from a laser light source and the scanner have the effect of making the source appear to move along a spherical path which compensates for the petzval curvature of the converging lens, thereby providing focusing on a flat field surface with a single focusing element.