| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which offers a wide view angle, a high zoom ratio, a large aperture ratio, and a compact optical system.SOLUTION: A zoom lens includes a first lens group having positive refractive power, a second lens group having negative refractive power, an aperture stop, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, arranged in order from the object side to the image side. When zooming in and out, the first lens group and the aperture stop do not move while each of the second, third, and fourth lens groups moves on a different track. Lateral magnifications &bgr;2w and &bgr;2t of the second lens group at a wide angle end and at a telephoto end and lateral magnifications &bgr;3w and &bgr;3t of the third lens group at the wide angle end and at the telephoto end are set appropriately. |
