Sony A77 has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz processor. On the other hand, Canon 1Ds MIII has a
21.0MP Full frame (36 x 24 mm ) sized CMOS sensor .
Below you can see the A77 and 1Ds MIII sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A77 and Canon 1Ds MIII Cameras
As seen above, Canon 1Ds MIII has a 2.4x Larger sensor area than Sony A77. 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. Sony A77 and Canon 1Ds MIII sensors have been tested by DxO and the results show that 1Ds MIII has a better overall score of 80, 2 points higher compared to A77's score of 78.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A77
78
24.0 bits
13.2 Evs
801 ISO
Canon 1Ds MIII
80
24.0 bits
12.0 Evs
1663 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 A77
or the
Canon 1Ds MIII ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-C versus Full frame),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.
