High magnification zoom lens for photography

Abstract

Abstract PURPOSE: To obtain a zoom lens which is extremely compact and is about 4 times in zoom ratios from standard to telephoto by using two sets of convergent lens groups and one set of divergent lens group and so constituting these as to satisfy predetermined conditions. CONSTITUTION: The lens system is constituted, successively from the object side, by three groups, the 1st convergent lens group, a divergent lens group and the 2nd convergent lens group, which are so constituted that variable powers are accomplished when the 1st convergent lens group and the 2nd convergent lens group in one form are mechanically moved together with the divergent lens group or variable powers are accomplished as these lens groups are mechanically moved respectively independently. These lens groups are so arranged that their conditions relating to the focal lengths and refractive indexes of the lens groups satisfy the conditions 1W4. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Sadao Okudaira

Bibliographic Details