Both Canon 1D X II and Olympus E-M1 II have 20.0 MP resolution sensors but Canon 1D X II's sensor is Full frame (36 x 24 mm ) and Olympus E-M1 II's sensor is Four Thirds (17.4 x 13 mm ).
Since Canon 1D X 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 Olympus E-M1 II.
One other difference between these two cameras that is worth mentioning is that Olympus E-M1 II's sensor doesn't have an 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 1D X MII and E-M1 II sensor size comparison.
As seen above, Canon 1D X II has a 3.8x Larger sensor area than Olympus E-M1 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 Canon 1D X II and Olympus E-M1 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, 1D X MII has scored 88, 8 points higher than E-M1 II.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Canon 1D X II |
88 |
24.1 bits |
13.5 Evs |
3207 ISO |
Olympus E-M1 II |
80 |
23.7 bits |
12.8 Evs |
1312 ISO |