Zoom lens group

A zoom lens group with seven lenses, sequentially comprising from an object side to an image side along an optical axis:

• a first lens group having a negative refractive power and comprising a first lens and a second lens, wherein the first lens has a positive refractive power, an object-side surface thereof is a convex surface, and an image-side surface thereof is a concave surface;
• a second lens group having a positive refractive power and comprising a third lens and a fourth lens;
• a third lens group having a refractive power and comprising a fifth lens and a sixth lens, wherein the fifth lens and the sixth lens are formed into a cemented lens;
• and
• a fourth lens group having a refractive power and comprising a seventh lens;
• and
• wherein by adjusting a spacing distance on the optical axis between the first lens group and the second lens group, a spacing distance on the optical axis between the second lens group and the third lens group and a spacing distance on the optical axis between the third lens group and the fourth lens group, the zoom lens group is switched from a long-focus state to a wide-angle state;
• a total effective focal length FT when the zoom lens group is in the long-focus state satisfies:
• 29 mm<FT<36 mm.