Polaroid (polarizer) Polaroid (polarizer) Polaroid is a type of synthetic plastic sheet which is used as a polarizer or polarizing filter. A trademark of the Polaroid Corporation, the term has since entered common use. The original material, patented in 1929 and further developed in 1932 by Edwin H. Land, consists of many microscopic crystals of iodoquinine sulphate (herapathite) embedded in a transparent nitrocellulose polymer film. The needle-like crystals are aligned during manufacture of the film by stretching or by applying electric or magnetic fields. With the crystals aligned, the sheet is dichroic: it tends to absorb light which is polarized parallel to
Polaroid i-Zone above the film. A mirror behind the lens would project the picture through the shutter onto the film below. One major marketing point for the camera was its ease of use: the camera had only three aperture settings, selected by a lever that pointed to a picture representing when each setting would be appropriate, be it indoors, outdoors on a sunny day, or outdoors on a cloudy day. After taking a photo, the lever would automatically revert to the off position to save power. Film for this camera was discontinued in 2006. Polaroid i-Zone The Polaroid i-Zone was a type