Although film and cameras are far more sophisticated and versatile today, the fundamental principles behind his inventions have not changed. A camera exposes an image on sensitized film. When exposed properly, photochemical changes occur in the photographic film. Later special developing and processing techniques reproduce the recorded image as a photographic negative, from which prints can be made. Color-reversal films produce positive images that can be mounted as slides.
Cameras are available in all shapes and sizes.
The aperture can be fixed, manually adjusted or automatically controlled. In some cameras, a light-sensitive cell adjusts the opening fo r varying light conditions. Simple cameras usually have a fixed lens opening. Shutter - A device that determines the length of time film is exposed to light entering the camera. The two chief parts of photographic film are its base and its light-sensitive emulsion.