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 SX-70 the company even produced small "600" AM/FM radios that would run on film packs in which the film cards had been exhausted, but the battery still had enough power to be reused. After Polaroid ceased manufacturing instant film in 2008, the Impossible Project (now Polaroid Originals) began formulating replacements using equipment acquired when the original manufacturing facilities closed. Polaroid's SX-70 "Time-Zero" film was phased out of production in late 2005 to early 2006 (differing according to regional markets). Small quantities of the film may still be acquired, however at often very highly inflated prices. Polaroid Originals produces lines of black