| 摘要 |
The invention provides a wide-angle lens capable of improving resolution while lowering cost. A wide-angle lens (20) has a four-group/six-lens configuration. Each of the six lenses has an aspheric plastic lens on the object side and/or the image side. A fourth lens group (14) (first cemented lens) in which aspheric surfaces are cemented together is included in the six lenses. A third lens group (13) (second cemented lens) in which aspheric-surface plastic lenses are cemented together is included on the side opposite the fourth lens group (14), with a diaphragm (91) interposed therebetween. The refractive indices of the cemented plastic lenses are symmetrical between the fourth lens group (14) (first cemented lens) and the third lens group (13) (second cemented lens) with respect to the diaphragm (91). |
