03 August 2009

Instant photography

The invention: Popularly known by its Polaroid tradename, a camera capable of producing finished photographs immediately after its film was exposed. The people behind the invention: Edwin Herbert Land (1909-1991), an American physicist and chemist Howard G. Rogers (1915- ), a senior researcher at Polaroid and Land’s collaborator William J. McCune (1915- ), an engineer and head of the Polaroid team Ansel Adams (1902-1984), an American photographer and Land’s technical consultant The Daughter of Invention Because he was a chemist and physicist interested primarily in research relating to light and vision, and to the materials that affect them, it was inevitable that Edwin Herbert Land should be drawn into the field of photography. Land founded the Polaroid Corporation in 1929. During the summer of 1943, while Land and his wife were vacationing in Santa Fe, New Mexico, with their three-yearold daughter, Land stopped to take a picture of the child. After the picture was taken, his daughter asked to see it. When she was told she could not see the picture immediately, she asked how long it would be. Within an hour after his daughter’s question, Land had conceived a preliminary plan for designing the camera, the film, and the physical chemistry of what would become the instant camera. Such a device would, he hoped, produce a picture immediately after exposure. Within six months, Land had solved most of the essential problems of the instant photography system. He and a small group of associates at Polaroid secretly worked on the project. Howard G. Rogers was Land’s collaborator in the laboratory. Land conferred the responsibility for the engineering and mechanical phase of the project on William J. McCune, who led the team that eventually designed the original camera and the machinery that produced both the camera and Land’s new film. The first Polaroid Land camera—the Model 95—produced photographs measuring 8.25 by 10.8 centimeters; there were eight pictures to a roll. Rather than being black-and-white, the original Polaroid prints were sepia-toned (producing a warm, reddish-brown color). The reasons for the sepia coloration were chemical rather than aesthetic; as soon as Land’s researchers could devise a workable formula for sharp black-and-white prints (about ten months after the camera was introduced commercially), they replaced the sepia film. A Sophisticated Chemical Reaction Although the mechanical process involved in the first demonstration camera was relatively simple, this process was merely the means by which a highly sophisticated chemical reaction— the diffusion transfer process—was produced. In the basic diffusion transfer process, when an exposed negative image is developed, the undeveloped portion corresponds to the opposite aspect of the image, the positive. Almost all selfprocessing instant photography materials operate according to three phases—negative development, diffusion transfer, and positive development. These occur simultaneously, so that positive image formation begins instantly. With black-and-white materials, the positive was originally completed in about sixty seconds; with color materials (introduced later), the process took somewhat longer. The basic phenomenon of silver in solution diffusing from one emulsion to another was first observed in the 1850’s, but no practical use of this action was made until 1939. The photographic use of diffusion transfer for producing normal-continuous-tone images was investigated actively from the early 1940’s by Land and his associates. The instant camera using this method was demonstrated in 1947 and marketed in 1948. The fundamentals of photographic diffusion transfer are simplest in a black-and-white peel-apart film. The negative sheet is exposed in the camera in the normal way. It is then pulled out of the camera, or film pack holder, by a paper tab. Next, it passes through a set of rollers, which press it face-to-face with a sheet of receiving material included in the film pack. Simultaneously, the rollers rupture a pod of reagent chemicals that are spread evenly by the rollers between the two layers. The reagent contains a strong alkali and a silver halide solvent, both of which diffuse into the negative emulsion. There the alkali activates the developing agent, which immediately reduces the exposed halides to a negative image. At the same time, the solvent dissolves the unexposed halides. The silver in the dissolved halides forms the positive image. Impact The Polaroid Land camera had a tremendous impact on the photographic industry as well as on the amateur and professional photographer. Ansel Adams, who was known for his monumental, ultrasharp black-and-white panoramas of the American West, suggested to Land ways in which the tonal value of Polaroid film could be enhanced, as well as new applications for Polaroid photographic technology. Soon after it was introduced, Polaroid photography became part of the American way of life and changed the face of amateur photography forever. By the 1950’s, Americans had become accustomed to the world of recorded visual information through films, magazines, and newspapers; they also had become enthusiastic picturetakers as a result of the growing trend for simpler and more convenient cameras. By allowing these photographers not only to record their perceptions but also to see the results almost immediately, Polaroid brought people closer to the creative process.