| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a zoom lens which has a compact optical system with a high zoom ratio and offers superior optical performance throughout an entire zoom range.SOLUTION: A zoom lens comprises first to fourth lens groups having positive, negative, positive, and positive refractive power arranged in order from the object side to the image side, and each lens group moves when zooming such that a distance between the first lens group and the second lens group increases while a distance between the second lens group and the third lens group decreases. Each of the first through third lens groups comprises one positive lens and one negative lens while the fourth lens group comprises one positive lens. An aperture stop is located between the third lens group and the fourth lens group. A distance D23t along an optical axis between the most object side lens surface of the second lens group and the most image side lens surface of the third lens group at a telephoto end, and a focal length ft of the entire system at the telephoto end are each set appropriately.</p> |
