The first camera released was the RB67 Professional in 1970. The system comprise of a camera body, viewfinder, back adapter, film back, and lens. The camera body itself is quite simple and fully mechanical. It does not require any battery power. The shutter button is located on the front bottom right of the camera. It can be locked with a twist of the collar. The shutter is cocked manually by pressing down the large lever on the right hand side of the body. The mirror within the camera and shutter in the lens are cocked at the same time. There are two focusing knobs on each side of the camera body similar to the Mamiya C series TLRs. The focusing screens are also interchangeable. The most common back adapter included in the system is the rotating back. The naming of the camera RB67 stood for Rotating Back 6 × 7.
The RB67 was originally designed to supplement the Mamiya C series 6 × 6 TLR system and the multi-format Mamiya Press rangefinder camera system (6 × 4.5, 6 × 7, 6 × 9, others) but has surpassed them in popularity. Back adapters for using Mamiya Press roll film and instant film backs are also available. Due to its heavy weight (almost 2kg for the body alone) the RB67 is often said to be unsuitable for use hand-held use. This isn't necessarily true - with a decent neck strap the RB67 can easily be used on the move. The flexibility of the RB67 system made it one of the most popular studio cameras in the 1970s