Provided is an imaging system such as a stereo camera which includes a mechanism capable of controlling a camera setting such as zooming or panning/tilting, wherein the stereo camera and the imaging system maintains measurement accuracy of the imaging system even when the camera setting is changed. The stereo camera including at least two cameras estimates camera parameters of the camera when a lens position of the camera is changed by an operation instruction of the camera. In addition, the imaging system includes at least two cameras, a camera control unit which controls at least a lens position of the camera, a calibration unit which estimates camera parameters of the camera when at least the lens position of the camera is moved by the camera control unit, and an image recognition unit which performs three-dimensional restoration of captured images of the cameras based on the camera parameters.