Ricoh K system

Ricoh's 35mm SLR system based on the original Pentax K mount. The most advanced cameras of the system featured an electronically controlled shutter and aperture-priority auto exposure mode, while conventional models had a mechanical shutter and offered manual exposure mode only. In order to implement shutter priority and programmed auto exposure modes, Ricoh had to modify the original mount and release a separate line of cameras and Rikenon P lenses.

NOTE:

• XR Rikenon prime lenses with focal lengths less than 28mm or more than 200mm were rebranded Sigma lenses,
• XR Rikenon prime lenses introduced in the 1990s were rebranded Cosina lenses,
• cameras introduced for this system in the 1990s-2000s were engineered and manufactured by Cosina,
• we decided not to record Rikenon zoom lenses since most of them were rebrands.