An imaging system includes a plurality of imaging apparatuses, each of the imaging apparatuses includes a detector for performing an imaging operation for outputting image data corresponding to applied radiation or light and a controller for controlling the operation of the detector. The imaging apparatuses can independently perform an imaging operation and are movable in accordance with a relative positional relationship thereof. Sensing means obtain information indicative of the relative positional relationship between the imaging apparatuses. A control computer sends a control signal for determining operations of the imaging apparatuses to the controller. The control computer determines the operations of the imaging apparatuses by using the information obtained from the sensing means; and sets an appropriate scanning direction of each of the imaging apparatuses in accordance with the positional relationship thereof.