Both Pentax K-500 and Olympus E-M5 II have 16.0 MP resolution sensors but Pentax K-500'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-500'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.
Below you can see the K-500 and E-M5 Mark II sensor size comparison.
As seen above, Pentax K-500 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-500 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-500 has scored 79, 6 points higher than E-M5 Mark II.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Pentax K-500 |
79 |
23.7 bits |
13.1 Evs |
1087 ISO |
Olympus E-M5 II |
73 |
23.0 bits |
12.4 Evs |
896 ISO |