PROBLEM TO BE SOLVED: To provide a large aperture photographing lens usable even in an electronic imaging element of a small image size.;SOLUTION: The large aperture photographing lens includes: a first lens group including at least a first lens of both-side convex lens, a second lens of positive refractive power having a convex face in an object side, a third lens of positive refractive power having a convex face in the object side, and a fourth lens of negative refractive power having a concave face in an image side, which are arranged sequentially from the object side, and fixed with a positive power when focused; a second lens group having lenses of positive refractive power and negative refractive power, having a negative power as an overall thereof, and moved from the object side to the image side, when focused from a distant point to a short distance; a lightness diaphragm; a third lens group having a positive power as the whole, and moved from the image side to the object side, when focused from the distant point to the short distance; and a fourth lens group including a lens of positive refractive power, and a lens of negative refractive power having a concave face in the image side with air therebetween, sequentially from the image side, having a positive power as an overall thereof, and fixed when focused.;COPYRIGHT: (C)2010,JPO&INPIT
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