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
Instant camera camera at the subject, framed it and took the photo. The camera and film did the rest, including adjusting the exposure settings, taking care of focusing (Sonar autofocus models only), utilising a flash if necessary (600 series and up), and ejecting the film, which developed without intervention from the photographer. The SX-70 instant camera (1972–1981) not only revolutionized the photographic market, but also influenced the art and way of taking photographs. Many photographers began to see the Polaroid as an unfinished canvas that needed a personal touch and, although some already retouched their snapshots before the appearance of the SX-70,