| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which offers a high zoom ratio, a wide view angle, superior optical performance over an entire zoom range, and reduced size in the optical axis direction.SOLUTION: A zoom lens comprises a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group having negative refractive power, and a fourth lens group having positive refractive power in order from an object side to an image side. Each lens group moves such that distance between the first lens group and the second lens group becomes smaller, distance between the second lens group and the third lens group becomes larger, and distance between the third lens group and the fourth lens group becomes larger at the telephoto end than at the wide angle end. A focal length f3 of the third lens group, a focal length f4 of the fourth lens group, a focal length fw of the entire system at the wide angle end, a focal length ft of the entire system at the telephoto end, and a sum Tsum of thickness of each lens group along the optical axis are each set appropriately. |
