Both Samsung NX20 and Sony A58 have APS-C sized 20.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the NX20 and A58 sensor size comparison.
Sensor Size and Resolution Comparison image of Samsung NX20 and Sony A58 Cameras
Samsung NX20 and Sony A58 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 Samsung NX20 and Sony A58 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, NX20 has scored 75, 1 points higher than A58.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Samsung NX20
75
23.4 bits
12.9 Evs
785 ISO
Sony A58
74
23.3 bits
12.5 Evs
753 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
Samsung NX20
or the
Sony A58 ,
including hyperfocal distance.
