Both Sony A65 and Nikon D5500 have 24.0 MP resolution sensors but Sony A65's sensor is APS-C (23.5 x 15.6 mm ) and Nikon D5500's sensor is APS-C (23.5 x 15.6 mm ).
Since Nikon D5500'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 Sony A65.
One other difference between these two cameras that is worth mentioning is that Nikon D5500's sensor doesn't have an 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 A65 and D5500 sensor size comparison.
Sony A65 and Nikon D5500 have the same sensor sizes so they will provide same level of control over the depth of field when used with 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 A65 and Nikon D5500 sensors have been tested by DxO and the results show that D5500 has a better overall score of 84, 10 points higher compared to A65's score of 74.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A65 |
74 |
23.4 bits |
12.6 Evs |
717 ISO |
Nikon D5500 |
84 |
24.1 bits |
14.0 Evs |
1438 ISO |