| 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 L 1 of positive refractivity closest to the subject, the second lens group L 2 of negative refractivity second closest to the subject, the third lens group L 3 of positive refractivity, and the fourth lens group L 4 of positive refractivity farthest from the subject, and the zoom lens satisfies the requirements 0.6<=|f 2 |/fW<=0.73 where f 2 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 f 3 is the focal length of the third lens group.
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