Patent ID: 7295380

Claim:
A zoom lens comprising: a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; a fourth lens group having a positive refracting power; and a fifth lens group having a negative refracting power, from an object side in this order, wherein a zooming operation is carried out by moving the second lens group and the fourth lens group; wherein the first lens group comprises: a front-side lens group having a negative refracting power; an optical element for folding an optical path; and a backside lens group having a positive refracting power, from the object side in this order; and wherein a condition of 1.3<β 5 <2.2 is satisfied, provided that an imaging magnification of the fifth lens group at a position where an object distance is at infinity is β 5 .