Both Pentax K-5 IIs and Olympus E-M5 II have 16.0 MP resolution sensors but Pentax K-5 IIs's sensor is APS-C (23.7 x 15.7 mm ) and Olympus E-M5 II's sensor is Four Thirds (17.3 x 13 mm ).
Since Pentax K-5 IIs'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-M5 II.
Another difference between these two cameras is that Pentax K-5 IIs'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 K-5 IIs and E-M5 Mark II sensor size comparison.
As seen above, Pentax K-5 IIs has a 1.7x Larger sensor area than Olympus E-M5 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 Pentax K-5 IIs and Olympus E-M5 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, K-5 IIs has scored 82, 9 points higher than E-M5 Mark II.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Pentax K-5 IIs |
82 |
23.9 bits |
14.1 Evs |
1208 ISO |
Olympus E-M5 II |
73 |
23.0 bits |
12.4 Evs |
896 ISO |