Both Olympus E-M10 II and Pentax K-5 have 16.0 MP resolution sensors but Olympus E-M10 II's sensor is Four Thirds (17.3 x 13 mm ) and Pentax K-5's sensor is APS-C (23.7 x 15.7 mm ).
Since Pentax K-5'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-M10 II.
Below you can see the E-M10 II and K-5 sensor size comparison.
As seen above, Pentax K-5 has a 1.7x Larger sensor area than Olympus E-M10 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
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It 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. Olympus E-M10 II and Pentax K-5 sensors have been tested by DxO and the results show that K-5 has a better overall score of 82, 9 points higher compared to E-M10 II's score of 73.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Olympus E-M10 II |
73 |
23.1 bits |
12.5 Evs |
842 ISO |
Pentax K-5 |
82 |
23.7 bits |
14.1 Evs |
1162 ISO |