ZOOM LENS

摘要

PROBLEM TO BE SOLVED: To attain excellent optical performance over all variable power ranges while shortening the total length of a lens. SOLUTION: In order from the object side, a first lens group I of a positive refractive power, a second lens group II of a negative refractive power, a third lens group III of a positive refractive power, a fourth lens group IV of a negative refractive power, a fifth lens group V of a positive refractive power and a sixth lens group VI of a negative refractive power are arranged. When zooming, the first lens group I, the third lens group III, the fifth lens group V and the sixth lens group VI are moved to the object side, respectively, and the second lens group II and the fourth lens group IV are fixed. At this point, focusing from an object at infinity to the closest range is performed by moving the sixth lens group VI to the image side. By representing an interval between an ith lens group and jth lens group at the wide-angle end by DW(i-j), an interval between an ith lens group and a jth lens group at the telescopic end by DT(i-j), the focal distance of the second lens group by f2 and the focal distance of the whole system at the telescopic end by fT, the following conditional relations are satisfied: DW(1-2)DT(2-3), DW(3-4)DT(4-5), DW(5-6)>DT(5-6), 0.1<|f2|/fT<0.18.