Both Sony A58 and Sony A3000 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 A58 and A3000 sensor size comparison.
Sony A58 and Sony A3000 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
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It 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. Sony A58 and Sony A3000 sensors have been tested by DxO and the results show that A3000 has a better overall score of 78, 4 points higher compared to A58's score of 74.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A58 |
74 |
23.3 bits |
12.5 Evs |
753 ISO |
Sony A3000 |
78 |
23.7 bits |
12.8 Evs |
1068 ISO |