| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens, which has a high variable magnification ratio even though a half field angle at a wide angle end is sufficiently a wide field angle that is 38 degrees or more, which is sufficiently corrected in aberration, and which has a resolving power adapted to an image pickup element of a small size and high resolution.SOLUTION: The zoom lens includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a positive refractive power, which are disposed in order from an object side. Accompanying the change of the magnification from the wide angle end to a telephoto end, an interval between the first and second lens groups G1 and G2 increases, an interval between the second and third lens groups G2 and G3 decreases, and an interval between the third and fourth lens groups G3 and G4 increases. The first lens group G1 includes a negative lens, a positive lens, and a positive lens, in order from the object side, the second lens group includes a negative lens, a positive lens, and a negative lens, and the third lens group includes a positive lens, a positive lens, and a negative lens, in order respectively. The Abbe's number and partial dispersion ratio of a specific lens of the third lens group are set in the range of predetermined condition expressions. |
