Sony A7S has a 12.0MP Full frame (35.8 x 23.9 mm ) sized CMOS sensor and features Bionz X processor. On the other hand, Canon 6D has a 20.0MP Full frame (36 x 24 mm ) sized CMOS sensor and features Digic 5+ processor.
Canon 6D's sensor provides 8MP more than Sony A7S'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 A7S and 6D sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A7S and Canon 6D Cameras
Sony A7S and Canon 6D have almost the same sensor size so none of them has any significant advantage over other in providing control over depth of field when used with same focal length and aperture.
DxOMark Sensor Scores
Both Sony A7S and Canon 6D 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, A7S has scored 87, 5 points higher than 6D.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A7S |
87 |
23.9 bits |
13.2 Evs |
3702 ISO |
Canon 6D |
82 |
23.8 bits |
12.1 Evs |
2340 ISO |