Canon 1Ds MIII has a
21.0MP Full frame (36 x 24 mm ) sized CMOS sensor . On the other hand, Sony A77 II has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz X processor.
Below you can see the 1Ds MIII and A77 II sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 1Ds MIII and Sony A77 II Cameras
As seen above, Canon 1Ds MIII has a 2.4x Larger sensor area than Sony A77 II. 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 1Ds MIII and Sony A77 II sensors have been tested by DxO and the results show that A77 II has a better overall score of 82, 2 points higher compared to 1Ds MIII's score of 80.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon 1Ds MIII
80
24.0 bits
12.0 Evs
1663 ISO
Sony A77 II
82
24.4 bits
13.4 Evs
1013 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 1Ds MIII
or the
Sony A77 II ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Full frame versus APS-C),
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.