The SX-70 is a folding single lens reflex Land camera which was produced by the Polaroid Corporation from 1972 to 1981.
SX-70 Model 2 with film cartridge protruding from the front
SX-70 Sonar One Step
A fully collapsed SX-70
In 1947, Polaroid introduced its first consumer camera. The Land Camera Model 95 was the first camera to use instant film to quickly produce photographs without developing them in a laboratory. The popular Model 95 and subsequent Land Cameras required complex procedures to take and produce good photographs. Photographic paper had to be manually removed from cameras, peeled open after 60 seconds, needed several minutes to dry, and often left developing chemicals on hands. The instructions for the Model 20 Swinger, introduced in 1965, warned that, if not followed, "you’re headed for plenty of picture taking trouble".
Pictures from the SX-70, by contrast, ejected automatically and developed quickly (fully within 10 minutes) without chemical residue. Polaroid founder Edwin H. Land announced the SX-70 at a company annual meeting in April 1972. On stage, he took out a folded SX-70 from his suit coat pocket and in ten seconds took five pictures, both actions impossible with previous Land Cameras. The company first sold the SX-70 in Miami, Florida in late 1972, and began selling it nationally in fall 1973. Although the high cost of $180 for the camera and $6.90 for each film pack of ten pictures ($1,100 and $42, respectively, adjusted for inflation) limited demand, Polaroid sold 700,000 by mid-1974. In 1973–4, the Skylab 3 and 4 astronauts used an SX-70 to photograph a video display screen to be able to compare the Sun's features from one orbit to the next.
There were a variety of models beginning in 1972 with the original SX-70, though all shared the same basic design. The first model had a plain focusing screen (the user was expected to be able to see the difference between in- and out-of focus) because Dr. Land wanted to encourage photographers to think they were looking at the subject, rather than through a viewfinder. When many users complained that focusing was difficult, especially in dim light, a split-image rangefinder prism was added. This feature is standard on all later manual focus models.
The later Sonar OneStep (introduced in 1978) and SLR 680 models were equipped with a sonar autofocus system. This sonar autofocus system greatly helped the user's ability to focus the camera, especially in dark environments, and could be turned off if manual focus was needed. The Sonar OneStep models were the first autofocus SLRs available to consumers. The later SLR 680/690 models updated the basic design of the Sonar OneStep to more modern standards by incorporating support for newer 600 film cartridges instead of SX-70 cartridges, and a built-in flash instead of the disposable "Flash Bar".