Both Canon 80D and Sony A6400 have APS-C sized 24.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the 80D and A6400 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 80D and Sony A6400 Cameras
Canon 80D and Sony A6400 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. Canon 80D and Sony A6400 sensors have been tested by DxO and the results show that A6400 has a better overall score of 83, 4 points higher compared to 80D's score of 79.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon 80D
79
23.6 bits
13.2 Evs
1135 ISO
Sony A6400
83
24.0 bits
13.6 Evs
1431 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
Canon 80D
or the
Sony A6400 ,
including hyperfocal distance.
