Patent ID: 7599127

Claim:
A zoom lens system composed of, in order from an object side: a first lens group having negative refractive power; and a second lens group having positive refractive power, and upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group varying, the first lens group being composed of two lens elements which are, in order from the object, a negative lens having a concave surface facing an image, and a positive lens, the second lens group consisting of three lens elements or less and including, in order from the object side, a positive lens, an aperture stop for defining an f-number, and a negative lens component including a negative lens and disposed to the image side of the aperture stop, at least one aspherical surface being included in both of the first lens group and the second lens group, focusing being carried out by the first lens group, and the following conditional expression being satisfied: −0.05 <Da/fw <0.5 where Da denotes a distance along the optical axis between the image side surface of the most object side positive lens in the second lens group and the aperture stop, and fw denotes a focal length of the zoom lens system in the wide-angle end state.