Patent ID: 8456747

Claim:
A zoom lens comprising, in order from an object side to an image side: a first lens unit having positive refractive power which does not move for zooming, and at least a part of which moves for focusing; a second lens unit adjacent to the first lens unit and having negative refractive power which moves for zooming; a third lens unit adjacent to the second lens unit and having positive refractive power which moves for zooming; a fourth lens unit having negative refractive power which moves for zooming; and a fifth lens unit having positive refractive power which does not move for zooming, wherein when fW denotes a focal length of the entire system of the zoom lens at a wide angle end, and Z denotes a zoom ratio, a focal length fM at an intermediate zoom position is expressed by the following equation: fM=fW×√Z, and wherein when L 2 W denotes an interval between the second lens unit and the third lens unit at the wide angle end, and L 2 max denotes a maximum value of the interval between the second lens unit and the third lens unit in a zoom range from the wide angle end to the focal length fM, the following conditional expression is satisfied: 1.1<L2max/L2W<55.0.