Wide-angle zoom lens

Abstract

Abstract PURPOSE: To obtain the wide-angle zoom lens which is small and light, has sufficient wide-angle effect, zoom effect and brightness and has further superior aberrations by letting the various specifications of the lens system of the 7-group 7-element constitution of front group 3 elements and rear group 4 elements satisfy the various specified conditions. CONSTITUTION: This is constituted by the 7-group 7-element lenses of front group 3 elements and rear group 4 elements, the respective group lenses being spaced mutually by air spacings. This lens is so constituted that the focal length of the entire system is changed by changing the spacing between the front group and rear group. Satisfying the various conditions of formulas (1)W(5) yields the wide- angle lens which provides sufficient wide-angle effect and zoom effect, has sufficient brightness for practicable use and is small. Further by satisfying the various conditions of formulas (6)W(9), coma aberrations, magnification chromatic aberrations, curvature of field and spherical aberrations may be corrected extremely well. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Masatoshi Kimura

Bibliographic Details