Both Sony A55 and Sony NEX-5R have APS-C sized 16.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the A55 and NEX-5R sensor size comparison.
Sony A55 and Sony NEX-5R have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the 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. Sony A55 and Sony NEX-5R sensors have been tested by DxO and the results show that NEX-5R has a better overall score of 78, 5 points higher compared to A55's score of 73.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A55 |
73 |
23.0 bits |
12.4 Evs |
816 ISO |
Sony NEX-5R |
78 |
23.7 bits |
13.1 Evs |
910 ISO |