| 摘要 |
A zooming optical system having six lens groups includes in order from an object side, a first lens group having a positive refracting power, which is fixed at the time of zooming, a second lens group having a negative refracting power, which is movable at the time of zooming, a third lens group having a positive refracting power, which is fixed at the time of zooming, a fourth lens group having a positive refracting power, which is movable at the time of zooming, a fifth lens group having a negative refracting power, which is movable at the time of zooming, and a sixth lens group having a positive refracting power, which is fixed at the time of zooming, and the first lens group includes a reflecting optical element for folding an optical path, and the third lens group includes an aperture stop, and the fifth lens group includes a single lens, and the zooming optical system satisfies the following conditional expression 0.5≦̸f1/√(fw·ft)≦̸2.0 where, f1 denotes a focal length of the first lens group, fw denotes a focal length of the overall zooming optical system at a wide angle end, and ft denotes a focal length of the overall zooming optical system at a telephoto end.
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