| 摘要 |
PROBLEM TO BE SOLVED: To provide a wide angle lens and a super-wide angle lens for an electronic image camera e.g. a video camera and a digital still camera, specially a wide angle lens having a viewing angle of about 75 deg. and a long back focal distance. SOLUTION: This wide angle lens is provided in order from an object side with a first lens groups G1 of a negative refractive power having a positive meniscus lens and at least one negative meniscus lens, a second lens group G2 of a positive refractive power, a diaphragm S and a third lens group G3 of a positive refractive power including a joined lens whose surface closest to the object side has a convex surface facing the object side and when the focal distance of the first lens group G1 is made to f1, the focal distance of the whole wide angle lens is made to (f) and a back focas is made to bf, the conditions; 0.5<|f1/f|<1.05 and 1.7<bf/f<4.0 are satisfied.
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