Canon 40D has a
10.0MP APS-C (22.2 x 14.8 mm ) sized CMOS sensor . On the other hand, Sony A390 has a
14.0MP APS-C (23.5 x 15.7 mm ) sized CCD sensor and features Bionz processor.
Below you can see the 40D and A390 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 40D and Sony A390 Cameras
As seen above, Sony A390 has a 1.1x Larger sensor area than Canon 40D. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in 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. Canon 40D and Sony A390 sensors have been tested by DxO and the results show that A390 has a better overall score of 66, 2 points higher compared to 40D's score of 64.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon 40D
64
22.1 bits
11.3 Evs
703 ISO
Sony A390
66
22.5 bits
11.5 Evs
607 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
Canon 40D
or the
Sony A390 ,
including hyperfocal distance.
