How do instant photographs work?

Developing a photo is one thing, but understanding the process is another one. Especially in the case of instant cameras, the complete process of developing a photo is compressed into several steps with a waiting time of only 15 seconds to 2 minutes.

First, the shutter release is pressed which opens the shutter and makes it possible for the light to penetrate the lenses and project a picture onto the photographic film. The shutter closes to avoid overexposure, and then developing process begins.

The film usually used is a composed of a negative and a positive side and a layer of chemicals, which make the instant developing possible.

While pulling the photo out of the camera the layers are compressed by two rolls inside the camera and the chemicals (developing agent) in the middle layer, between the negative and positive, are spread between the sheets. The negative develops quickly and by the silver halide grains the picture is projected onto the positive. After the indicated developing time the negative is separated from the positive and the final picture is fully developed.