Both Sony A77 and Sony A77 II have 24.0 MP resolution sensors but Sony A77's sensor is APS-C (23.5 x 15.6 mm ) and Sony A77 II's sensor is APS-C (23.5 x 15.6 mm ).
Since Sony A77 II'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 A77.
Below you can see the A77 and A77 II sensor size comparison.
Sony A77 and Sony A77 II 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 A77 and Sony A77 II sensors have been tested by DxO and the results show that A77 II has a better overall score of 82, 4 points higher compared to A77's score of 78.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A77 |
78 |
24.0 bits |
13.2 Evs |
801 ISO |
Sony A77 II |
82 |
24.4 bits |
13.4 Evs |
1013 ISO |