Patent ID: 8279532

Claim:
A zoom lens system comprising a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a positive refractive power; the first, second, and third lens groups being arranged sequentially from an object side; when the zoom lens system is zoomed from a wide angle position to a telephoto position, an interval between the first lens group and the second lens group decreases and an interval between the second lens group and the third lens group increases; the first lens group comprising a first lens, a second lens, and a third lens arranged sequentially from the object side; and the zoom lens system satisfying the following expression: 0.25≦( fw×N 2)/ ft≦ 0.34, wherein fw indicates a focal length of the zoom lens system at the wide angle position, ft indicates a focal length of the zoom lens system at the telephoto position, and N2 indicates a refractive index of the second lens of the first lens group.