The SX-70 is a folding single lens reflex Land Camera which was produced by the Polaroid Corporation from 1972-1977.
Though Polaroid had considered a Henry Dreyfus-designed SLR for its Colorpack film, the SX-70 was the first instant SLR and the first camera to use Polaroid's new SX-70 integral print film, which developed automatically without the need for intervention from the photographer. The SX-70 was also notable for its elegant folding design, which allowed the camera to be compact enough to fit a man's suit-jacket pocket when collapsed.
There were a variety of models beginning in 1972 with the original SX-70, though all shared the same basic design. The first model, sold in Florida in late 1972, 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, Dr. Land was forced to include a split-image rangefinder prism of the kind used on 35mm SLR focusing screens. This feature is standard on the SX-70 Model 2.
The later Sonar OneStep and SLR 680 models were equipped with a sonar autofocus system, which permitted returning to the plain focusing screen. The Sonar Onestep models were the first autofocus SLRs available to consumers. (Polaroid Corporation marketed this relatively inexpensive, novel sonar technology as a set of components to hobbyists in order for them to incorporate distance sensing into other systems.) The later SLR 680/690 models updated the basic design of the Sonar Onestep to more modern standards by incorporating support for newer 600 cartridges instead of SX-70 cartridges, and a built-in flash instead of the disposable Flash bar. Today they are the most evolved forms of the SX-70, and are highly sought after by Polaroid enthusiasts.
Though expensive, the SX-70 was popular in the 1970s and retains a cult following today.