In a zoom lens device of the present invention, an aperture at a predetermined zooming step that is other than a telephoto end and a wide-angle end is smaller than apertures at the other zooming steps, and the predetermined zooming step is used only when a macro shooting mode is chosen. The clamp includes a first base and a second base removeably coupled to a crib. Furthermore, APs can perform automatic power adjustment so that multiple APs can operate on the same channel while minimizing interference with each other.