An exemplary embodiment is directed to a zoom lens system configured to impart an appropriate refractive power to an image stabilizing lens unit. The zoom lens system can include: a first lens unit; a second lens unit; and a rear lens group. The plurality of lens units constituting the rear lens group can contain a lens component, where the lens component can include: a front lens sub-component; and a rear lens sub-component. Moreover, in at least one further exemplary embodiment at least a part of the front lens sub-component or the rear lens sub-component can be moved.