Zoom lens and imaging apparatus including the same

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.