How Do Old Film Cameras Work

The Film

Old cameras work using a special thin strip of film. The film is treated with a special light sensitive chemical that works by causing a chemical change when sunlight strikes the film. The more light exposed to the film, the more exposed the film will become. Too much light can overexpose the film, completely ruining the photo.

The Lens

The lens controls how much light focuses on the film. The lens uses a field of focus to determine how large the image will be on the film, as well as how clear the image will be when developed.

The Shutter

Though the lens focuses the light, it's the shutter that is the actual light control. By using the shutter you can choose a long or short exposure (to light) to control the finished image on the film.

The Iris

The iris works by further reducing the exposure light to the film. The aperture located inside the iris also changes the field of focus to allow objects both close to the camera and far away from the camera to stay clear and sharp. Without the iris parts of the image would remain blurry.

Film Developing

One of the fundamental differences between old film cameras and new digital cameras is the developing process. With digital cameras there is no film. This removes many of the problems associated with exposing the film. In film cameras, the film is developed using chemicals called couplers. As each type of coupler is exposed to the film it creates a different color. The exposure to the couplers also seals the film so that it is no longer sensitive to light.