| 摘要 |
PROBLEM TO BE SOLVED: To provide a lens system that: has a telephoto side brighter than F2.0; includes a wide angle area; has a zooming ratio of about 3.5 times; has a small front lens diameter; and can be compactly housed in a collapsed state.SOLUTION: A zoom lens includes: a positive first lens group and a negative second lens group, from an object side; and a positive third lens group and its subsequent lens group on an image side. An air interval between the first and second groups is larger than a wide angle end at a telephoto end, and an air interval between the second group and the third group is larger than the telephoto end at the wide angle end. The first group is composed of two lenses of one negative lens and one positive lens. The second group is composed of five lenses including three negative lenses and two positive lenses that are, from the object side, a negative 21 lens, a negative 22 lens, a positive 23 lens, and subsequent lenses. The negative 22 lens and the positive 23 lens are composed of a cemented lens having a cemented surface having a convex surface facing the object side. A predetermined conditional expression is satisfied.SELECTED DRAWING: Figure 1 |
