Cushman, Darby & Cushman
Large aperture telephoto lens system
 A large-aperture telephoto lens system with high telephoto ratio wherein a negative thick meniscus lens is arranged in the rear lens group for correcting the negative spherical aberration and negative coma which are produced by the positive meniscus lenses with high refractive indices positioned on the object side. 
Olympus Optical Co., Ltd.
G
G02B
inventional
Toru
Fujii