In a camera, a zoom lens and focus lens are driven to predetermined positions corresponding to a zoom magnification factor to be changed upon a demand for altering the zoom magnification factor. During a zooming operation after the camera has been brought into focus by an auto-focusing function, driving rates of the zoom lens and focus lens are controlled in each of zoom intervals to set driving times required to drive the zoom lens and focus lens to positions corresponding to the next zoom magnification factor to the quickest zoom driving time Tz of the zoom lens and the longer driving time among the quickest focus driving times Tfa, Tfb of the focus lens corresponding to object distances.