Patent ID: 7518805

Claim:
A zoom lens system comprising, in order from an object side thereof: a first lens group that has positive refractive power; a second lens group that has negative refractive power; a third lens group that has positive refractive power; a fourth lens group that has positive refractive power; and a fifth lens group that has positive refractive power, wherein the third lens group consists, in order from the object side, of a first positive lens, a negative lens, and a second positive lens, the first positive lens and the negative lens composing a cemented lens, the fourth lens group consists, in order from the object side, of a first positive lens, a negative lens, and a second positive lens, the negative lens and the second positive lens composing a cemented lens, zooming between a wide-angle end and a telephoto end is carried out without moving the first lens group and the fifth lens group, and focusing is carried out by moving the fifth lens group.