Lens system capable of short distance photography
AssigneeNippon Kogaku K.K.
InventorYoshinari Hamanishi
Life of this patent
Estimating the term…
Abstract
Compact lens systems capable of continuously effecting infinity photography to high magnification proximity photography and having a large aperture ratio and excellent imaging performance comprise, in order from the object side, a first convergent lens group, a second convergent lens group including a diaphragm, and a third divergent lens group. The first and second groups are movable toward the object side relative to the third group, while enlarging their spacing, when focusing is effected from infinity to a short distance.
Claims10
A lens system capable of continuously effecting infinity photography to high magnification proximity photography, comprising:
- a convergent lens group which is a first group positioned most adjacent to the object side;
- a convergent lens group which is a second group positioned rearwardly of said first group;
- a divergent lens group which is a third group positioned rearwardly of said second group;
- and
- a diaphragm provided between said first group and said third group;
- said first group and said second group being movable toward the object side relative to said third group while enlarging the spacing between said first and second groups when focusing is effected from infinity to a short distance, and the diaphragm being movable with the second group.
Dependencies are inferred from the claim text.