A term used in aerial photography meaning the point of origin of bundles of perspective rays. The two such points usually associated with survey photographs are the interior perspective center and the exterior perspective center. In a perfect lens camera system, perspective rays from the interior perspective center to the photographic image enclose the same angles, as do the corresponding rays from the exterior perspective center to the subject photographed. In a lens with distortion, this is true only for a particular zone of the photograph. In a perfectly adjusted lens camera system, the exterior and the interior perspective centers correspond, respectively, to the front and rear nodal points of the camera lens.
