| 摘要 |
A taking lens for an underwater camera is constituted in the order from the side of a subject of a first lens group having no or slight refracting power, a second lens group having a positive refracting power, a third lens group having positive refracting power and a fourth lens group having negative refracting power. When focusing from the infinity to a closer distance, the first lens group is fixed to the image surface and the second and third lens groups are moved forward along the optical axis such that the distance between the second and third lens groups is changed.
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