The Olympus OM system was late to the game, but ended up changing the rules of SLR design entirely. Introduced in 1972, this system turned the idea of big, heavy, metal 35mm SLRs on its head by being compact without sacrificing the build or image quality that made SLRs popular.
Yoshihisa Maitani, designer of the Olympus PEN and XA, also led the design team for the first OM SLR, the OM-1. It and the other single-digit OM series SLRs were designed to fit all the professional-grade features customers wanted in a body that anyone could carry around. The consumer-grade two-digit models, like the OM-10, are less well-built but come at a lower price point.
Olympus produced and sold OM series SLRs until 2002 when the company pivoted to digital cameras using the Four Thirds and Micro Four Thirds mounts.