To provide a compact-sized large-diameter zoom lens with high optical performance ranging from a visible region to a near-infrared region.
A zoom lens comprises a negative first lens group L1 and a positive second lens group L2. A diaphragm SP is disposed between the first lens group L1 and the second lens group L2. The second lens group L2 includes at least four lenses 4 to 7, or more. At least one lens surface of the lens 4 located closest to the object side among the four lenses is aspherical. At least one lens surface of the lens 7 located closest to the image side is aspherical. A lens surface of the third lens 6 from the object side, the lens surface being on the object side, is convex. The relations of 65<νd22 and R22a/R22b<0 are satisfied where νd22 is the Abbe number of the second lens 5 from the object side, R22a is the radius of curvature of the lens surface on the object side, and R22b is the radius of curvature of the lens surface on the image side.
| JP2008065051A | 2008-03-21 | |||
| JP2009205055A | 2009-09-10 | |||
| JP2006091643A | 2006-04-06 | |||
| JP2010008917A | 2010-01-14 |
Masatake Shiga
Takashi Watanabe
Shinya Mitsuhiro