Mamiya's super-telephoto for the RB system — the rare 500mm f/6 APO for medium format wildlife.
The Mamiya RB 500mm f/6 APO L is a rare super-telephoto lens for the Mamiya RB67 medium format system. At 500mm on 6x7 format, it provides approximately a 250mm equivalent perspective — serious telephoto reach on medium format. The APO designation indicates apochromatic correction for superior colour fringing control. The L designation suggests a later production version.
Optical performance is impressive for the specification. The APO correction provides excellent chromatic aberration control — essential at this focal length. Sharpness is good when stopped down. The 6x7 format combined with 500mm creates extreme telephoto compression effects not achievable on smaller formats. A highly specialised tool for medium format telephoto work.
Mamiya RB mount with leaf shutter. Weight is substantial — likely over 2 kg. Build quality is professional grade with the APO L designation indicating premium construction. Manual focus. The RB system's rotating back allows format switching between landscape and portrait orientation without rotating the entire heavy camera and lens assembly.
Very rare on the used market — the RB 500mm was produced in limited numbers. Prices vary widely based on condition. Check leaf shutter operation and clean APO elements. Only of interest to Mamiya RB system owners wanting extreme medium format telephoto reach. A fascinating piece of medium format lens engineering.