Both Samsung GX-20 and Pentax K20D have APS-C sized 15.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the GX-20 and K20D sensor size comparison.
Sensor Size and Resolution Comparison image of Samsung GX-20 and Pentax K20D Cameras
Samsung GX-20 and Pentax K20D 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
Both Samsung GX-20 and Pentax K20D 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, GX-20 has scored 68, 3 points higher than K20D.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Samsung GX-20
68
23.1 bits
11.2 Evs
714 ISO
Pentax K20D
65
22.9 bits
11.1 Evs
639 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 GX-20
or the
Pentax K20D ,
including hyperfocal distance.
