How instant photographs work

Instant photography is remarkable because it encompasses every individual step of photography, from the actual taking of a photograph to the developing process. The instant camera has basically a built in dark room, where traditionally the photographs are developed. The film in the instant camera is a piece of plastic paper with many layers, containing light-sensitive grains. Every layer reacts to another color. While regular film has only the layers with the light-sensitive grains, instant film contains every necessary chemical substance required for developing the photograph. First there are additional layers of developing chemicals between every light-sensitive layer. These layers are all placed on a base layer or also called black layer.  Above these light-sensitive layers is the image layer the timing layer, the acid layer and a clear plastic layer that covers up the whole picture. The arrangement of the layers is crucial for the chemical reaction to be set in motion. The reagent chemical is the essential component that causes the reaction. It  is  collected in a bulb on the side of the paper. When taking a picture, the light-sensitive layers absorb the light energy. When this happened, the film is pushed through two stainless steel rolls that break the bulb and spreads the reagent across the picture. The reagent is pressed in right between the image layer and the light-sensitive layer. This reagent contains opacifiers and alkali, which both react with the light-sensitive layer and the layers above. It starts the chemical reaction in the light-sensitive layers by changing the particles into metallic silver. Then the particles that were struck by the light, travel up into the image layer. After the film was tossed through the rolls, it comes out of the camera but the image is not visible yet. This is because the chemical reaction has not ended yet. The opacifiers in the reagent allows the film to be exposed to light because it blocks the light from reaching the other layers. The acid layer in reaction with alkali will make the opacifiers become clear. The timing layer is responsible for slowing down the reagent, to give the film enough time to develop. This is the reason why it takes some time until the image becomes visible on the film.

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