Sony A9 III has a
24.6MP Full frame (35.6 x 23.8 mm ) sized Global Shutter sensor and features BIONZ XR processor. On the other hand, Nikon Z6 II has a
24.0MP Full frame (35.9 x 23.9 mm ) sized BSI-CMOS sensor and features Dual Expeed 6 processor.
Another difference between these two cameras is that Sony A9 III'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 A9 Mark III and Z6 Mark II sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A9 III and Nikon Z6 II Cameras
Sony A9 III and Nikon Z6 II 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 A9 III and Nikon Z6 II sensors have been tested by DxO and the results show that Z6 Mark II has a better overall score of 94, 7 points higher compared to A9 Mark III's score of 87.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A9 III
87
24.1 bits
13.0 Evs
3224 ISO
Nikon Z6 II
94
25.0 bits
14.4 Evs
3303 ISO
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Sony A9 III
or the
Nikon Z6 II ,
including hyperfocal distance.
