Both Nikon Z8 and Nikon Z7 II have Full frame sized 46.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
One other difference between these two cameras that is worth mentioning is that Nikon Z7 II'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 Z8 and Z7 Mark II sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon Z8 and Nikon Z7 II Cameras
Nikon Z8 and Nikon Z7 II have the same sensor sizes so they will provide same level of control over the depth of field when used with 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 Z8 and Nikon Z7 II sensors have been tested by DxO and the results show that Z7 Mark II has a better overall score of 100, 2 points higher compared to Z8's score of 98.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon Z8
98
26.3 bits
14.2 Evs
2548 ISO
Nikon Z7 II
100
26.3 bits
14.7 Evs
2841 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
Nikon Z8
or the
Nikon Z7 II ,
including hyperfocal distance.
