Patent ID: 8643959

Claim:
A zoom lens comprising, in order from an object side to an image side and arranged along an optical axis thereof: a first lens unit having positive refractive power; a second lens unit having negative refractive power; a third lens unit having positive refractive power; and a fourth lens unit having positive refractive power, wherein the first lens unit includes a cemented lens obtained by cementing negative and positive lenses in order from the object side to the image side, the second lens unit includes negative, negative, and positive lenses in order from the object side to the image side, the third lens unit includes positive and negative lenses in order from the object side to the image side, and the fourth lens unit includes a positive lens, wherein, during zooming from a wide-angle end to the telephoto end, the first to fourth lens units move such that a distance between the first and second lens units increases, a distance between the second and third lens units decreases, and a distance between the third and fourth lens units increases, and wherein the following conditions are satisfied: 1.0< M 3/ M 1<3.0, and 2.5< f 1/ f 3<8.0, where M 1 and M 3 denote movement amounts of the first and third lens units, respectively, during zooming from the wide-angle end to a telephoto end, and f 1 and f 3 denote focal lengths of the first and third lens units, respectively.