Both Olympus E-PM2 and Sony NEX-5T have 16.0 MP resolution sensors but Olympus E-PM2's sensor is Four Thirds (17.3 x 13 mm ) and Sony NEX-5T's sensor is APS-C (23.4 x 15.6 mm ).
Since Sony NEX-5T'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-PM2.
Below you can see the E-PM2 and NEX-5T sensor size comparison.
As seen above, Sony NEX-5T has a 1.6x Larger sensor area than Olympus E-PM2. 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-PM2 and Sony NEX-5T sensors have been tested by DxO and the results show that NEX-5T has a better overall score of 78, 6 points higher compared to E-PM2's score of 72.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Olympus E-PM2 |
72 |
22.7 bits |
12.2 Evs |
932 ISO |
Sony NEX-5T |
78 |
23.6 bits |
13.0 Evs |
1015 ISO |