Wide-angle objective lens system for wide-angle camera, has transparent protective plane plate disposed before wide-angle objective, and entrance aperture gathering light from object over diagonal field angle of specific degrees

摘要

The system has a wide-angle objective with a set of lenses, and a transparent protective plane plate disposed before the wide-angle objective. An entrance aperture (4) gathers light from an object over a diagonal field angle of 118 degrees. An optical iris (6) arranged behind a lens group (2), and another lens group (8) is arranged behind the optical iris. The lens group (8) projects the light from the lens group (2) which passes through the iris to impinge on an image surface with an image distortion of lesser than 3 percent.