Zoom lens

A zoom lens, comprising:

• a first lens group having a positive refractive power, the first lens group comprising a first lens and a second lens arranged in sequence from an object side to an image side, and refractive powers of the first lens and the second lens respectively being negative and positive;
• a second lens group having a negative refractive power and disposed between the first lens group and the image side, the second lens group comprising a third lens, a fourth lens and a fifth lens arranged in sequence from the object side to the image side, and refractive powers of the third lens, the fourth lens and the fifth lens respectively being negative, negative and positive;
• a third lens group having a positive refractive power and disposed between the second lens group and the image side, the third lens group comprising a sixth lens, and a refractive power of the sixth lens being positive;
• and
• a fourth lens group having a positive refractive power and disposed between the third lens group and the image side, the fourth lens group comprising a seventh lens, an eighth lens and a ninth lens arranged in sequence from the object side to the image side, refractive powers of the seventh lens, the eighth lens and the ninth lens respectively being positive, negative and positive, and at least one of the seventh lens, the eighth lens and the ninth lens being an aspheric lens.