Optical system for camera

摘要

An optical system for a compound camera includes an equivalent image plane provided at a position substantially optically equivalent to an image plane of the photographing lens system. A condenser lens is provided proximate to the equivalent image plane and a relay lens system is provided behind the condenser lens to form an image of the photographing lens system on an image pickup device. The relay lens system satisfies the requirements defined by -0.1<P<0.09, and S3<0, where P designates the Petzval sum of the whole relay lens system when the focal length of the relay lens system is assumed to be 1.0, and S3 designates the astigmatism coefficient of the whole relay lens system when the focal length thereof is assumed to be 1.0, respectively.