Sony A7 IV has a
33.0MP Full frame (35.8 x 23.8 mm ) sized BSI-CMOS sensor and features Bionz XR processor. On the other hand, Nikon Z9 has a
46.0MP Full frame (35.9 x 23.9 mm ) sized Stacked CMOS sensor and features Expeed 7 processor.
Nikon Z9's sensor provides 13MP more than Sony A7 IV'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.
Another difference between these two cameras is that Sony A7 IV's sensor lacks 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 IV and Z9 sensor size comparison.
Sony A7 IV and Nikon Z9 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 IV and Nikon Z9 sensors have been tested by DxO and the results show that Z9 has a better overall score of 98, 1 points higher compared to A7 IV's score of 97.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A7 IV |
97 |
25.4 bits |
14.7 Evs |
3379 ISO |
Nikon Z9 |
98 |
26.3 bits |
14.8 Evs |
2451 ISO |