Ricoh GXR A16 24-85mm has a
16.0MP APS-C (23.6 x 15.7 mm ) sized CMOS sensor and features Smooth Imaging Engine IV processor. On the other hand, Ricoh GXR Mount A12 has a
12.0MP APS-C (23.6 x 15.7 mm ) sized CMOS sensor .
Below you can see the GXR A16 24-85mm F3.5-5.5 and GXR Mount A12 sensor size comparison.
Ricoh GXR A16 24-85mm and Ricoh GXR Mount A12 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Ricoh GXR Mount A12 has 31% larger pixel area (30.35µm2 vs 23.04µm2) compared to Ricoh GXR A16 24-85mm, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.