发明名称 WIDE-ANGLE LENS, OPTICAL APPARATUS, AND METHOD FOR FOCUSING WIDE-ANGLE LENS
摘要 PROBLEM TO BE SOLVED: To provide a wide-angle lens having higher optical performance, an optical apparatus using thereof, and a method for focusing the wide-angle lens. SOLUTION: The wide-angle lens includes, in order from an object, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power. Upon focusing to an object, the first lens group G1 is fixed, and the second lens group G2 and the third lens group G3 are moved to the object side. The second lens group G2 includes a negative refractive power lens component L21 to the most object side, and the following conditional expression is satisfied: -f1/f>6.00, where f denotes a focal length of the entire system, and f1 denotes a focal length of the first lens group G1. COPYRIGHT: (C)2009,JPO&INPIT
申请公布号 JP2009193053(A) 申请公布日期 2009.08.27
申请号 JP20080291344 申请日期 2008.11.13
申请人 NIKON CORP 发明人 HARADA MASAKI
分类号 G02B13/04;G02B13/18;G03B5/00 主分类号 G02B13/04
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