Tesser type objective lens system having a rear aperture stop

摘要

An improved tesser type objective lens system having a rear aperture stop with a relatively wide field angle of about 60 DEG and an F-number of about F 2.8 is provided. The thickness of the second negative lens in the lens system is increased relative to the total axial distance of the lens system which permits the reduction of the Petzval sum while maintaining a balance correction of spherical aberration and coma.