| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens having a high optical performance in the whole power variation range, having a comparatively short back focus, and whose optical whole length is short and having a high variation range up to power variation ratio of 4 to 5, and to provide optical equipment using the zoom lens. SOLUTION: The zoom lens is provided with 1st, 2nd and 3rd lens groups (L1 to L3) having positive, positive and negative refractive power, respectively, in this order from an object side, and the power is varied by moving the lens groups so that an axial air distance between the 1st lens group L1 and the 2nd lens group L2 may become longer at a telephoto end as compared with a wide angle end and an axial air distance between the 2nd lens group 2 and the 3rd lens group L3 may become shorter. In this case, the 2nd lens group L2 is composed of a 21st lens group L21 constituted of a bi-concave negative lens and a positive lens and a 22nd focusing lens group L22 in this order from the object side, and the focal distance of the 1st lens group L1, the focal distance of the 3rd lens group L3 and the focal distance of the whole system at the wide angle end and the telephoto end are appropriately set.
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