Instant-Picture Photography




This person is removing an instantly developed photograph from a Polaroid camera in 1948.





This person is removing an instantly developed photograph from a Polaroid camera in 1948.

BLACK-AND-WHITE DIFFUSION TRANSFER

The Polaroid process is based on negative paper carrying a silver halide emulsion and a nonsensitized, positive sheet containing development nuclei. After the exposure the two sheets are brought into intimate contact by being pulled between a pair of pressure rollers. These rupture a sealed pod (attached to the positive sheet) to spread processing chemicals—in the form of a viscous jelly—between the two sheets. This reagent develops a negative image and causes the silver salts from the unexposed areas to diffuse into the positive layer and deposit metallic silver on the development nuclei. After about 30 seconds to one minute the negative and positive sheets are peeled apart and the negative can be discarded. In special versions of the process the negative may be washed and treated to give a conventional negative for normal enlarging.

POLAROID CORPORATION

The Polaroid Corporation, also called Primary PDC, Inc., is an American manufacturer of cameras, film, and optical equipment founded by Edwin Herbert Land (1909–91), who invented instant photography.

The company originated in 1932 as the Land-Wheelwright Laboratories, which Land founded with George Wheelwright to produce Land's first invention, an inexpensive plastic-sheet light polarizer. By 1936 Land began to use polarized material in sunglasses and other optical devices, and in 1937 the company was incorporated under the Polaroid name.

After Land retired as chief executive officer in 1980, Polaroid continued to develop new products for professional, technical, and consumer markets. These included cameras, high-speed film, floppy disks, medical equipment, colour-transparency films, transparent cameras, and identity verification equipment for security systems. In 1986 Polaroid won a $925-million judgment from the Eastman Kodak Company for patent infringement. In the 1990s Polaroid delivered more firsts to the industry, including cameras with picture-storage compartments, and introduced several products that were worldwide best sellers, such as the redesigned Polaroid OneStep camera. In 1996 the corporation released its first digital camera.

Silver diffusion-transfer processes were invented in 1939 in Belgium and Germany and were used for a number of years in office copying systems until superseded by dry copying processes.

THE POLACOLOR PROCESS

Polaroid colour film has a larger number of active layers, including a blue-sensitive silver halide emulsion backed by a layer consisting of a yellow dye–developer compound, a green-sensitive layer backed by a layer of magenta dye–developer, and a red-sensitive layer backed by a cyan dye–developer. The dye–developer in each case consists of dye molecules (not colour couplers) chemically linked to developing agent molecules.

SINGLE-SHEET PROCESS

The Polaroid single-sheet, or integral, films contain all the negative and positive layers in a single preassembled film unit that is exposed through the transparent positive layer. The unit incorporates a viscous processing reagent that acts in principle similarly to the chemistry of the Polacolor process. It includes “opacifying” dyes and a highly opaque white pigment that together protect the negative layers against light during processing outside the camera. The pigment provides a background to the positive image after the dye–developer molecules from the negative layers have migrated into the receiving layer. Other constituents of the system neutralize residual active chemicals after processing, for all chemistry remains within the single-sheet print. The print size is about 3 1/2 × 4 1/4 inches, the effective image size about 3 1/8 × 3 1/8 inches. The Eastman Kodak and Fuji Photo Film companies also have marketed single-sheet films and cameras that accept each other's films. These materials and cameras are not compatible with the Polaroid products.




In the Polaroid Autoprocess system, Polaroid Instant 35-mm transparency films—Polarchrome, Polapan, and Polagraph were developed in a daylight processor to yield a filmstrip of dry images in less than three minutes.





In the Polaroid Autoprocess system, Polaroid Instant 35-mm transparency films—Polarchrome, Polapan, and Polagraph—were developed in a daylight processor to yield a filmstrip of dry images in less than three minutes.
AUTOPROCESS MATERIALS

APPLICATIONS