The SX-70 included many sophisticated design elements. A collapsible SLR required a complex light path for the viewfinder, with three mirrors (including one Fresnel reflector) of unusual, aspheric shapes set at odd angles to create an erect image on the film and an erect aerial image for the viewfinder. Many mechanical parts were precision plastic moldings. The body was made of glass-filled polysulfone, a rigid plastic which was plated with a thin layer of copper-nickel-chromium alloy to give a metallic appearance. Models 2 & 3 used ABS in either Ebony or Ivory color. The film pack contained a flat, 6-volt "PolaPulse" battery to power the camera electronics, drive motor and flash. The original flash system, a disposable "Flash Bar" of 10 bulbs (five on each side, with the user rotating the bar half way through) from General Electric, used logic circuits to detect and fire the next unused flash.
Although a variety of models were offered, all share the same basic design. All SX-70 models feature a folding body design, a 4-element 116mm f/8 glass lens, and an automatic exposure system. The cameras allow for focusing as close as 10.4 inches (26.4 cm), and have a shutter speed range from 1/175s to more than 10 seconds. The Model 3 departs from the other models since it isn't a SLR, but instead has the viewfinder cut into the mirror hood. A whole array of accessories could be utilized with SX-70 cameras, such as a close-up lens (1:1 @ 5 inches), electrical remote shutter release, tripod mount and an Ever-Ready carrying case that hung from the neck and unfolded in concert with the camera.
A lot of the technology used in the folding SX-70 cameras was later used in the production of rigid "box" type SX-70 cameras, such as the Model 1000 OneStep, Pronto, Presto and The Button. These models, although also utilizing SX-70 film, are very different from the folding SLR SX-70s.