1. A monitor system for capturing an image of a monitoring area, the system comprising: a plurality of cameras connected via a communication path, wherein each camera of the plurality of cameras includes: an image capturing device operable to capture an image of an image capturing area included in the monitoring area, and to change the image capturing area; a communication unit operable to transmit, to another camera via the communication path, image capturing characteristics information for identifying the image capturing area, and to receive image capturing characteristics information from said another camera; an image capturing characteristics change unit operable to change the image capturing area by controlling the camera based on the image capturing characteristics information of the camera and the image capturing characteristics information of said another camera received by said communication unit so that the image capturing area of the camera and the image capturing area of said another camera have a predetermined relation, and wherein the image capturing characteristics information includes information for identifying a position of the image capturing area, and said image capturing characteristics change unit includes: a cooperation partner determination unit operable to identify another camera whose image capturing area is adjacent to the image capturing area of the camera; an area difference evaluation unit operable to provide an overlapping area evaluation value for an overlapped area in which the image capturing area of said another camera which has been identified and the image capturing area of the camera overlap each other, based on the image capturing characteristics information from said another camera and the image capturing characteristics information of the camera; and an image capturing area change unit operable to change the image capturing area of the camera so as to generate the overlapped area by controlling said camera so that the overlapping area evaluation value approaches a predetermined overlapping area target value so as to form a gapless wide range image, the overlapping area evaluation value being provided by said area difference evaluation unit.