A camera system which comprises a photo-taking lens assembly of varifocal type including a zooming lens and a focusing lens; a manipulatable member; a zooming drive device for driving the zooming lens during a manipulation of the manipulatable member; a focusing device for driving the focusing lens; a focal length detector for sequentially detecting a current focal length of the photo-taking lens assembly; a zooming amount calculator operable to repeatedly add or subtract a predetermined amount to or from the current focal length during the manipulation of the manipulatable member thereby to sequentially update a target focal length used as a reference for the drive of the zooming lens; a first control adapted to receive the target focal length updated by the zooming amount calculator for calculating the amount of deviation in focus which would occur before the target focal length is attained and also for controlling the focusing device so as to eliminate the amount of deviation in focus which has been calculated; and a second control for controlling the zooming drive device, when the manipulation of the manipulatable member is released, so as to drive the zooming lens to a position where the target focal length calculated by the zooming amount calculator is attained.
