| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens whose entire system is compact and which has a high zoom ratio and high optical performance over the entire zoom range.SOLUTION: The zoom lens includes, in order from an object side to an image side, a first lens group having a positive refractive power, a second lens group L2 having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power. When zooming from a wide angle end to a telephoto end, the lens groups move so that the distance between the first lens group and the second lens group L2 increases, the distance between the second lens group L2 and the third lens group decreases, and the distance between the third lens group and the fourth lens group increases. Each of the first lens group, the second lens group L2 and the third lens group comprises one positive lens and one negative lens, and the fourth lens group comprises one positive lens. The focal length fw of the entire system at the wide angle end, the focal length ft of the entire system at the telephoto end, the focal length f1 of the first lens group, and the focal length f2 of the second lens group L2 are appropriately set, respectively. |
