Both Nikon A and Sony A57 have APS-C sized 16.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the A and A57 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon A and Sony A57 Cameras
Nikon A and Sony A57 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
Both Nikon A and Sony A57 sensors have been tested by DxoMark. DxoMark 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. Of the two cameras that we are comparing, A has scored 80, 5 points higher than A57.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon A
80
23.4 bits
13.8 Evs
1164 ISO
Sony A57
75
23.4 bits
13.0 Evs
785 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 A
or the
Sony A57 ,
including hyperfocal distance.
