Both Ricoh GXR A12 50mm and Pentax Q10 have 12.0 MP resolution sensors but Ricoh GXR A12 50mm's sensor is APS-C (23.6 x 15.7 mm ) and Pentax Q10's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Ricoh GXR A12 50mm's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Pentax Q10.
Below you can see the GXR A12 50mm F2.5 Macro and Q10 sensor size comparison.
Sensor Size and Resolution Comparison image of Ricoh GXR A12 50mm and Pentax Q10 Cameras
As seen above, Ricoh GXR A12 50mm has a 13.2x Larger sensor area than Pentax Q10. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Ricoh GXR A12 50mm
or the
Pentax Q10 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-C versus 1/2.3-inch),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.
