| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens with high optical performance having a vibration proof mechanism and a quiet and high-speed focus mechanism, and achieving reductions in size, weight and cost.SOLUTION: The zoom lens includes, in order from the object side to the image plane side: a first lens group L1 having a positive refractive power; a second lens group L2 having a negative refractive power and being fixed with respect to the image plane; an aperture stop S; a third lens group L3 having a positive refractive power; a fourth lens group L4 having a negative refractive power; and a fifth lens group L5. The second lens group L2 comprises three lenses. When focusing from an infinite distance to a close distance, the fourth lens group L4 moves toward the image plane side along the optical axis. When zooming from the wide angle end to the telephoto end, each of the lens groups moves along a predetermined locus. The zoom lens satisfies predetermined conditional expressions. |
