| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which has excellent optical performance over the entire zoom range including a standard zoom area and a short back focus, is compact, and can excellently correct a camera shake.SOLUTION: The zoom lens comprises, in order from an object side to an image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a subsequent lens group. The subsequent lens group includes, in order from the object side, a first partial group having positive refractive power, a second partial group having negative refractive power, and a third partial group having positive refractive power. In the zoom lens, the relation among a composite focal length f12w when focusing at infinity at the wide-angle end of the first lens group and the second lens group, a composite focal length f3Rw when focusing at infinity at the wide-angle end of the lens group on the image side from the third lens group, a focal length fis of the second partial group in the subsequent lens group, a composite focal length fRt when focusing at infinity at the telephoto end of the subsequent lens group, a focal length f1 of the first lens group, and a focal length fw at the wide-angel end of the entire zoom lens system is properly set. |
