Sony A390 has a
14.0MP APS-C (23.5 x 15.7 mm ) sized CCD sensor and features Bionz processor. On the other hand, Fujifilm X100 has a
12.0MP APS-C (23.6 x 15.8 mm ) sized CMOS sensor and features EXR processor.
One other difference between these two cameras that is worth mentioning is that Fujifilm X100's sensor doesn't have an anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the A390 and X100 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A390 and Fujifilm X100 Cameras
Sony A390 and Fujifilm X100 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 A390 and Fujifilm X100 sensors have been tested by DxO and the results show that X100 has a better overall score of 73, 7 points higher compared to A390's score of 66.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A390
66
22.5 bits
11.5 Evs
607 ISO
Fujifilm X100
73
22.9 bits
12.4 Evs
1001 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
Sony A390
or the
Fujifilm X100 ,
including hyperfocal distance.
