The Mamiya RB67 series, the world's first medium format 6x7cm single lens reflex with unique revolving back, was first introduced in 1970. Its unique built-in revolving back and bellows focusing made it an instant success that lasted for decades to a world-wide status as the "workhorse of the pros".
Mamiya RB67 series lenses were available in focal lengths ranging from fisheye to extreme telephoto, and include special application lenses for Variable Soft Focus, PC shift, Variable Flat Field Macro, Zoom, and an exceptional series of K/L APO Series apochromatic telephotos. K/L series lenses were optically identical to the ultra-high performance RZ series lens designs, while they utilized fully mechanical leaf shutters.