Both Olympus E-420 and Olympus E-510 have Four Thirds sized 10.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the E-420 and E-510 sensor size comparison.
Sensor Size and Resolution Comparison image of Olympus E-420 and Olympus E-510 Cameras
Olympus E-420 and Olympus E-510 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 Olympus E-420 and Olympus E-510 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, E-420 has scored 56, 4 points higher than E-510.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Olympus E-420
56
21.5 bits
10.4 Evs
527 ISO
Olympus E-510
52
21.2 bits
10.0 Evs
442 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
Olympus E-420
or the
Olympus E-510 ,
including hyperfocal distance.
