Both Pentax K-500 and Sony NEX-3N 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 K-500 and NEX-3N sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax K-500 and Sony NEX-3N Cameras
Pentax K-500 and Sony NEX-3N 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 Pentax K-500 and Sony NEX-3N 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, K-500 has scored 79, 5 points higher than NEX-3N.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax K-500
79
23.7 bits
13.1 Evs
1087 ISO
Sony NEX-3N
74
22.8 bits
12.5 Evs
1067 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
Pentax K-500
or the
Sony NEX-3N ,
including hyperfocal distance.
