Patent ID: 8786714

Claim:
A zoom lens comprising: a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group including a first sub-lens group having a positive refractive power, an iris, and a second sub-lens group having a positive refractive power; and a fourth lens group having a positive refractive power, wherein the first to fourth lens groups are sequentially arranged from an object side to an image side, the distance between each of the first to fourth lens groups changes when zooming from a wide angle position to a telephoto position, the surface of the lens closest to the image side in the first sub-lens group is concave, the lens closest to the object side in the second sub-lens group is a meniscus lens concave towards the object side, and the lens closest to the object side in the third lens group is an aspheric lens, wherein the zoom lens satisfies the conditions: Vd2≧60 Vd3≧70, where Vd 2 denotes an Abbe number of a negative lens included in the second lens group, and Vd 3 denotes an Abbe number of a lens included in the third lens group.