Nikon Df has a
16.0MP Full frame (36 x 23.9 mm ) sized CMOS sensor and features Expeed 3 processor. On the other hand, Sony A9 has a
24.0MP Full frame (35.6 x 23.8 mm ) sized Stacked BSI-CMOS sensor and features BIONZ X processor.
Sony A9's sensor provides 8MP more than Nikon Df'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 Df and A9 sensor size comparison.
Nikon Df and Sony A9 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. Nikon Df and Sony A9 sensors have been tested by DxO and the results show that A9 has a better overall score of 92, 3 points higher compared to Df's score of 89.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Nikon Df |
89 |
24.6 bits |
13.1 Evs |
3279 ISO |
Sony A9 |
92 |
24.9 bits |
13.3 Evs |
3517 ISO |