| 摘要 |
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.
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