The Ricoh GXR is a remarkable camera. It is built by a unique concept, where changing a lens means you also change the sensor.
Ricoh Launched the GXR in november 2009. It was designed to be a Compact System Camera (CSC), which means it is a small camera and it featured exchangeable lenses. But Ricoh decided to not just manufacture exchangeable lenses, but incorporate lens and sensor in a single unit, called a ‘lensor’. The idea behind this was simple: different lenses could benefit from different sensor sizes.
The A12 GXR Mount lensor isn’t quite a lensor, in that it has no lens incorporated! Instead it has a Leica M mount in the unit that also houses an APS-C 12MP sensor.