Patent ID: 8649106

Claim:
A zoom lens comprising in order from an object side to an image side: a first lens unit of positive refractive power; a second lens unit of negative refractive power; a third lens unit of positive refractive power; and a rear lens group having one or more lens units, wherein during zooming from a wide-angle end to a telephoto end, the distance between the first lens unit and the second lens unit increases, the distance between the second lens unit and the third lens unit decreases, and the distance between the third lens unit and the rear lens group changes, wherein the first lens unit consists of, in order from the object side to the image side, a positive lens and a negative lens, and wherein the following conditional expressions are satisfied: 8.0< f 1/ fW< 30.0 and 2.0<β2 T/β 2 W< 10.0, where f 1 is a focal length of the first lens unit, fW is a focal length of the entire system at the wide-angle end, and β 2 W and β 2 T are respectively lateral magnifications of the second lens unit at the wide-angle end and the telephoto end.