| 摘要 |
PROBLEM TO BE SOLVED: To obtain a rear focusing type zoom lens having five lens groups as a whole, which performs focusing with the lens group behind a variable power system, whose entire lens system is miniaturized, whose variable power ratio is about 16 to 20, and whose back focusing is long. SOLUTION: This lens has a first group L1, having positive refracting power, a second group L2 and a third lens group L3 having negative refracting power, and a fourth lens group and a fifth lens group having the positive refracting power in order from an object side, variable power is performed by the movement of the group L2, image surface fluctuation caused by the variable power is compensated by the group L3, and focusing is performed by the movement of the group L5. In this case, when the focal distance of the group L5 is defined as f5, and the focal distance at a wide angle end is defined as fw, and a conditional expression of 4.0<f5/fw<8.0 is to be satisfied.
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