Large aperture ratio telephoto lens system

摘要

A high-performance large aperture ratio telephoto lens system comprising a first lens group having positive refractive power, a second lens group having negative refractive power and a third lens unit having positive refractive power, the large aperture ratio telephoto lens system being arranged to fulfill the conditions shown below and to have the focal length about 200 mm to 300 mm and F number about F2. (1) 0.4f<fI<0.8f (2) 0.2f<¦fII¦<0.5f (3) 0.3f<FIII<0.8f.