Zoom lens and camera with zoom lens

A zoom lens comprising, sequentially from an object side thereof, a first lens elements group having a negative refraction power as a whole, a second lens elements group having a positive refraction power as a whole, and a third lens element group having a negative refraction power as a whole, wherein a variable power is realized by shifting positions of the first lens elements group and the second lens elements group in a direction of an optical axis thereof, or by shifting, in addition to the positions of the first lens elements group and the second lens elements group, a position of the third lens element group in a direction of an optical axis thereof,

• wherein the first lens elements group is made up by disposing, sequentially from an object side thereof, a first lens element which is a negative lens, which has a negative refraction power, a second lens element which is a positive lens, which has a positive refraction power, and a third lens element which is a negative lens, and
• wherein the zoom lens satisfies the following conditional expression (1) with respect to a power of the first lens elements group, the following conditional expression (2) with respect to a size of the whole lens system, and the following conditional expression (3) with respect to a power of the third lens element group, the following conditional expression (4) with respect to a power of the second lens element, the following conditional expression (5) with respect to dispersion properties that are distributed to each lens element of the first lens elements group, and the following conditional expression (6) with respect to a refractive index of the second lens element:
• −0.8≦fw/fI≦−0.45 (1)
• 4.5≦TLw/fw≦7.5 (2)
• −0.55≦fw/fIII≦0 (3)
• 0.22≦fw/f2≦0.55 (4)
• 15≦(υ1+υ3)/2−υ2 (5)
• 1.65≦n2 (6)
• where:
• fw:
• composite focal length of the whole lens system at a wide-angle end;
• fI:
• composite focal length of the first lens elements group;
• fIII:
• composite focal length of the third lens element group;
• TLw:
• distance from an object side surface of the first lens element, which is positioned closest to the object side among lens elements of the first lens elements group, to an image plane at the wide-angle end (where, a parallel plane glass portion is converted into an air space distance);
• f2:
• focal length of the second lens element of the first lens elements group;
• υ1:
• Abbe number of the first lens element of the first lens elements group;
• υ2:
• Abbe number of the second lens element of the first lens elements group;
• υ3:
• Abbe number of the third lens element of the first lens elements group;
• n2:
• refractive index relative to the d line of the second lens element of the first lens elements group.