Polaroid SX-70 | Fetch Gadgets

The demonstration in a suit pocket

Polaroid's earlier Land Cameras, from the Model 95 of 1948 onward, made their own photographs, but the process asked a good deal of the owner. The print had to be pulled from the camera by hand, peeled open after 60 seconds, coated with a chemical stabiliser so it would survive, and developing fluid could end up on the fingers. The instructions shipped with the Model 20 Swinger in 1965 warned that a user who ignored them was headed for plenty of picture taking trouble.

Edwin H. Land, Polaroid's founder and the primary driver of the project, announced the SX-70 at the company's annual meeting in April 1972. He took a folded camera out of his suit coat pocket and, in ten seconds, produced five photographs. Retail sales began in Miami, Florida, in late 1972 and went national in the autumn of 1973.

The optics behind a folding SLR

Folding the body meant folding the light path with it. The SX-70 viewfinder used three mirrors, one of them a Fresnel reflector, shaped as aspheres and set at odd angles so that the owner saw an erect image and the film received one too. Most mechanical parts were precision plastic mouldings rather than machined metal. The Model 1 body was moulded in glass-filled polysulfone and plated with a thin copper-nickel-chromium layer for a metallic finish; Models 2 and 3 moved to ABS in ebony or ivory.

Every folder shared a four-element 116 mm f/8 glass lens and an automatic exposure system Polaroid called the Electric Eye. Focus was manual and could close to 10.4 inches (26 cm). Shutter speeds ran from 1/175 second to more than 10 seconds. Light came from a disposable Flash Bar holding ten General Electric bulbs, five to a side, rotated halfway through, with logic circuits that fired the next unused bulb.

The film pack carried the battery

Each SX-70 film pack held ten sheets with a picture area of 3.125 inches square, rated at ISO 150, and, unusually, a flat 6 volt Polapulse battery built into the pack itself. The zinc chloride cell drove the camera motors and exposure electronics, so a fresh battery arrived with every pack and the camera never needed one of its own. Polaroid later published development kits for using the Polapulse battery outside photography.

Prints ejected automatically and finished developing within about ten minutes. The trade was price. The camera listed at $180 and a pack of ten pictures at $6.90, roughly $1,385 and $53 in later money, and that kept demand narrow at first. Even so, Polaroid had sold 700,000 by the middle of 1974.

The first autofocus SLR, and a camera for orbit

A split-image rangefinder prism took the place of the plain matte focusing screen once buyers complained that focusing in dim light was guesswork. The Alpha 1 of 1977 added a tripod socket and strap lugs. The SX-70 Sonar OneStep of 1978 carried an ultrasonic ranging system that prefocused on a half press and could be switched off when manual focus was wanted, which made it the first autofocus SLR sold to consumers. The line closed with the SLR 680 and, in 1996, the SLR 690, bodies that accepted the faster 600 film and carried their own electronic flash.

The camera also went to work. In 1973 and 1974, crews on the Skylab 3 and 4 missions used an SX-70 to photograph a video display screen so that the Sun's features could be compared from one orbit to the next.

Prints that could be pushed around with a thumb

Because the SX-70 emulsion is gelatin based and its Mylar cover does not readily pass water vapour, a finished print stayed soft for days, and its owner could press the chemistry around with a fingertip or a blunt tool to smear colour like wet paint. Manipulation works best about two minutes after the image has fully developed and stays possible for five to fifteen minutes. Lucas Samaras built a series of self-portraits, the Photo-Transformations of 1973 to 1976, out of the technique, and a manipulated SX-70 image became the cover of Peter Gabriel's third self-titled album in 1980.

Photographers treated the camera as a serious instrument. Ansel Adams, Andy Warhol and Helmut Newton used it, Newton for fashion work, and Walker Evans took it up in 1973 at the age of 70. Real popularity arrived with a cheaper body. The $40 Model 1000 OneStep was the best selling camera of the 1977 Christmas shopping season.

The film stops, then restarts

The original film was revised in the middle of the 1970s and then replaced in 1980 by SX-70 Time-Zero Supercolor, whose reformulated layers developed faster and produced stronger colour. Time-Zero was manufactured until December 2005, and remaining stock had sold out by March 2006. When Polaroid stopped making instant film altogether in 2008, the Impossible Project acquired the old manufacturing equipment and began formulating replacements, rebranding as Polaroid Originals in 2017 and later trading simply as Polaroid. Modern SX-70 film is compatible but not identical: it uses different chemistry, develops more slowly and is more sensitive to light and pressure. The 600 packs introduced in 1981 fit the same bodies but run at ISO 640 rather than ISO 150, about two stops faster, so a folding SX-70 needs a neutral density filter or a converted exposure circuit to expose them correctly.