Today, May 7, is the birthday of scientist and inventor Edwin H. Land. Land was born on May 7, 1909 and is known mostly for his inventing of the Polaroid instant camera. Happy Birthday Mr. Land!! Land also co-founded the Polaroid Corporation in 1937. Among other things, Land invented inexpensive filters for polarizing light, a practical system of in-camera instant photography. His Polaroid instant camera, which went on sale in late 1948, made it possible for a picture to be taken and developed in 60 seconds or less.
The trick to the Polaroid camera is in the film itself. The film contains three silver compounds. When these compounds are exposed to a large number of light photons, it forms silver atoms. In the color film typically used with the Polaroid camera, the top layer is sensitive to blue light, the next layer is sensitive to green and the bottom layer is sensitive to red. When the film was exposed, the sensitive grains at each layer react to light of that color, creating a chemical record of the light and color pattern. Underneath each color layer, there is a developer layer containing dye couplers. All of these layers sit on top of a black base layer, and underneath the image layer, the timing layer and the acid layer. This arrangement is a chemical chain reaction waiting to be set in motion.
Check out this video below to see exactly how a Polaroid camera works!