Patent ID: 7423810

Claim:
A zoom lens system comprising: a plurality of lens units each composed of at least one lens element, wherein an interval between at least any two lens units among the lens units is changed so that an optical image of an object is formed with a continuously variable magnification, any one of the lens units, any one of the lens elements, or alternatively a plurality of adjacent lens elements that constitute one lens unit move in a direction perpendicular to an optical axis, the zoom lens system, in order from the object side to the image side, comprises: a first lens unit having positive optical power; a second lens unit that includes a lens element having a reflecting surface for bending a light beam from an object and that has negative optical power; a third lens unit having positive optical power; and a fourth lens unit having positive optical power, and the following condition (1) is satisfied: 1.00<−(1 −m 2T )× m 3T ×m 4T <2.00 (1) in which, m 2T is a magnification of the second lens unit at a telephoto limit in a case that the shooting distance is infinity, m 3T is a magnification of the third lens unit at a telephoto limit in a case that the shooting distance is infinity, m 4T is a magnification of the fourth lens unit at a telephoto limit in a case that the shooting distance is infinity, f W is a focal length of the entire zoom lens system at a wide-angle limit, and f T is a focal length of the entire zoom lens system at a telephoto limit.