| 摘要 |
A macro lens system which includes a positive first lens group, a negative second lens group, a positive third lens group, and a negative fourth lens group, in this order from the object. Upon focusing from an infinite photographing distance to the closest photographing distance, the second lens group moves towards the image, and the third lens group moves toward the object. The macro lens system satisfies the following condition:whereinf designates the focal length of the entire lens system at an infinite photographing distance;m designates the transverse magnification at the closest photographing distance; andDELTAX3 designates the traveling distance of the third lens group from the infinite photographing distance to the closest photographing distance.
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