| 摘要 |
A macro lens system includes a positive first lens group, a negative second lens group, a positive third lens group, and a negative fourth lens group, in that order from the object. Upon focusing from an infinite photographic distance to a life-sized photographic distance, the first lens group remains stationary with respect to the imaging plane, and the second and third lens groups move along the optical axis direction. The macro lens system satisfies the following condition: −4.6<f2/fi<−3.0 wherein f2 designates the focal length of the second lens group; and fi the focal length of the entire the macro lens system when an object at infinity is in an in-focus state. |
