Camera-attachment lens system

摘要

A camera-attachment lens system includes a positive condenser lens system and a positive image-forming lens system, and satisfies the following conditions: 1.5<fa/fco<2.4 (1) 0.08<DO/fa<0.16 (2) 1.65<Nco (3) wherein fa: the combined focal length of the condenser lens system and the image-forming lens system; fco: the focal length of the condenser lens system; DO: the distance from the image-forming plane of the objective optical system to the most objective-optical-system side surface of the condenser lens system; and Nco: the refractive index of the condenser lens system.