This model was based on the P-8 CINESTAR S, launched in 1965, with improvements made to accommodate a 400-foot reel. Switching between Regular 8 and Super 8/Single 8 was as simple as a single touch of a lever. The S-400 had an automatic loading and rewinding system like its predecessor. It also featured a 17-28mm f/1.3 zoom lens and a push-button slow-motion function.