| 摘要 |
A first group (10) having a negative refractive power, a diaphragm (St) and a second group (20) having a positive refractive power are arranged in order from the object side. Power variation from the wide angle end to the telephoto end is executed by moving the second group (20) to the object side along an optical axis. Correction of an image plane associated with the power variation is made by moving the first group (10) along the optical axis. The second group (20) includes a first lens (L21) having at least one aspheric surface and having a positive refractive power; a cemented lens formed of a second lens (L22) having a positive refractive power and a third lens (L23) having a negative refractive power; a fourth lens (L24) having a negative refractive power; and a fifth lens (L25) having a positive refractive power in order from the object side.
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