| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which has a large aperture ratio and a compact total system, is well corrected for various aberrations such as spherical aberration, coma aberration, and field curvature, and easily provides high optical performance.SOLUTION: A zoom lens comprises, in order from the object side to the image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power and, when zooming from the wide-angle end to the telephoto end, the first lens group and the fourth lens group are stationary while the second lens group and the third lens group move and distance between the first lens group and the second lens group increases. The zoom lens includes an aperture stop, and a focal length fl of the first lens group, a focal length f3 of the third lens group, a total length TL of the lens, and an air-equivalent distance DSP from the aperture stop at the telephoto end to an image plane are each set appropriately. |
