Both Pentax RZ18 and Ricoh GXR A16 24-85mm have 16.0 MP resolution sensors but Pentax RZ18's sensor is 1/2.3-inch (6.08 x 4.56 mm ) and Ricoh GXR A16 24-85mm's sensor is APS-C (23.6 x 15.7 mm ).
Since Ricoh GXR A16 24-85mm'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 RZ18.
Below you can see the RZ18 and GXR A16 24-85mm F3.5-5.5 sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax RZ18 and Ricoh GXR A16 24-85mm Cameras
As seen above, Ricoh GXR A16 24-85mm has a 13.4x Larger sensor area than Pentax RZ18. 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
Pentax RZ18
or the
Ricoh GXR A16 24-85mm ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/2.3-inch versus APS-C),
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.
