Both Olympus E-M1 II and Canon G9 X II have 20.0 MP resolution sensors but Olympus E-M1 II's sensor is Four Thirds (17.4 x 13 mm ) and Canon G9 X II's sensor is 1″ (13.2 x 8.8 mm ).
Since Olympus E-M1 II'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 Canon G9 X II.
Another difference between these two cameras is that Olympus E-M1 II's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the E-M1 II and G9 X II sensor size comparison.
Sensor Size and Resolution Comparison image of Olympus E-M1 II and Canon G9 X II Cameras
As seen above, Olympus E-M1 II has a 1.9x Larger sensor area than Canon G9 X II. 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.
DxOMark Sensor Scores
Both Olympus E-M1 II and Canon G9 X II sensors have been tested by DxoMark. DxoMark scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Of the two cameras that we are comparing, E-M1 II has scored 80, 15 points higher than G9 X II.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Olympus E-M1 II
80
23.7 bits
12.8 Evs
1312 ISO
Canon G9 X II
65
21.9 bits
12.5 Evs
522 ISO
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-M1 II
or the
Canon G9 X II ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Four Thirds versus 1″ ),
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.
