Sony A7 III has a
24.0MP Full frame (35.8 x 23.8 mm ) sized BSI-CMOS sensor and features Bionz X processor. On the other hand, Nikon D810 has a
36.0MP Full frame (35.9 x 24 mm ) sized CMOS sensor and features EXPEED 4 processor.
Nikon D810's sensor provides 12MP more than Sony A7 III'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.
One other difference between these two cameras that is worth mentioning is that Nikon D810'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 A7 III and D810 sensor size comparison.
Sony A7 III and Nikon D810 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. Sony A7 III and Nikon D810 sensors have been tested by DxO and the results show that D810 has a better overall score of 97, 1 points higher compared to A7 III's score of 96.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A7 III |
96 |
25.0 bits |
14.7 Evs |
3730 ISO |
Nikon D810 |
97 |
25.7 bits |
14.8 Evs |
2853 ISO |