A process by which chemically sensitized surfaces are exposed to light (photo) and retain an image (graph) of what is exposed. Methods may be very simple to highly complex. Camera are usually used with adjustable lenses (apertures) and controlled light levels on light sensitive film. The film is then processed (developed) and the image is "fixed" (made permanent). The image (a negative) is transferred onto treated papers, enlarged and processed with chemicals in a "dark room" to make the photographs (also called prints).