Both Olympus E-M10 III and Pentax XG-1 have 16.0 MP resolution sensors but Olympus E-M10 III's sensor is Four Thirds (17.4 x 13 mm ) and Pentax XG-1's sensor is 1/2.3 (6.17 x 4.55 mm ).
Since Olympus E-M10 III'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 XG-1.
Below you can see the E-M10 III and XG-1 sensor size comparison.
Sensor Size and Resolution Comparison image of Olympus E-M10 III and Pentax XG-1 Cameras
As seen above, Olympus E-M10 III has a 8.1x Larger sensor area than Pentax XG-1. 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
Olympus E-M10 III
or the
Pentax XG-1 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Four Thirds versus 1/2.3),
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.
