Sony A77 II has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz X processor. On the other hand, Sony A57 has a
16.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor .
Sony A77 II's sensor provides 8MP more than Sony A57's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the A77 II and A57 sensor size comparison.
Sony A77 II and Sony A57 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. On the other hand, since Sony A57 has 49% larger pixel area (22.87µm2 vs 15.28µm2) compared to Sony A77 II, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.
DxOMark Sensor Scores
Both Sony A77 II and Sony A57 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, A77 II has scored 82, 7 points higher than A57.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A77 II |
82 |
24.4 bits |
13.4 Evs |
1013 ISO |
Sony A57 |
75 |
23.4 bits |
13.0 Evs |
785 ISO |