| 摘要 |
The present invention is directed to a high variable power zoom lens that ensures a flange-back or a backfocal distance required for typical 35-mm film cameras while keeping an angle of view sufficient to cover the wide-angle for an APS-size imaging plane dimensioned smaller than 35 mm. The high variable power zoom lens has the first lens group L1 of positive refractivity closest to the subject, the second lens group L2 of negative refractivity second closest to the subject, the third lens group L3 of positive refractivity, and the fourth lens group L4 of positive refractivity farthest from the subject, and the zoom lens satisfies the requirements 0.6‰ | f 2|/ fW ‰ 0.73 where f2 is the focal length of the second lens group and fW is the focal length of the entire optics moved to the wide-angle end, and also satisfies the requirements 2.2‰ f 3/ fW ‰ 3.7 where f3 is the focal length of the third lens group.
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