Lens system for close distance photographing

Abstract

Abstract PURPOSE: To let the lens system have a large diameter and have always superior imaging performance in the photographing regions from infinite far up to near distance by providing an iris between the the front group and rear group having positive refracting power. CONSTITUTION: The lens system is constituted by the front group G 1 having positive refracting power, the rear group G 2 likewise having poisitive refractive power and the iris provided between the both groups. And condition formulas (1), (2) are satisfied. At the focusing from an infinitely far object to a close distance object, both groups are moved to the object side while increasing air spacing between the both groups. Such change in the iris spacing enables aberrations to be corrected extremely well. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Yoshinori Hamanishi

Bibliographic Details