| 摘要 |
PROBLEM TO BE SOLVED: To obtain a zoom lens whose variable power rate is high, for example, 3-6 by constituting this zoom lens of 6 zoom lens groups with prescribed refractive power. SOLUTION: This zoom lens is provided with 6 lens groups, that is, a first group L1 with a positive refractive power, second group L2 with a negative refractive power, third group with a positive refractive power, fourth group L4 with a negative refractive power, fifth group L5 with a positive refractive power, and sixth group L6 with a negative refractive power successively from an object side. In this case, at the time of varying a power from a wide angular edge to a telephoto edge, when air intervals at the wide angular edge and telephoto edge of the (i)th and (i+1)th groups are respectively DiW and DiT, a condition that D1W<D1T, D2W>D2T, D3W<D3T, D4W>D4T, and D5W>D5T is fulfilled by moving the prescribed lens group, and when image formation magnification at the telephoto edge of the third group isβ3T, the focal distance of the (i)th group is fi, and the focal distance of the whole system at the telephoto edge is fT, a condition that -1.5<β3T<-0.25 and 0.05<f5/fT<0.185 is fulfilled.
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