Both Nikon D5 and Canon 1Ds MIII have Full frame sized 21.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the D5 and 1Ds MIII sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D5 and Canon 1Ds MIII Cameras
Nikon D5 and Canon 1Ds MIII 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
Both Nikon D5 and Canon 1Ds MIII sensors have been tested by DxoMark. DxoMark 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. Of the two cameras that we are comparing, D5 has scored 88, 8 points higher than 1Ds MIII.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon D5
88
25.1 bits
12.3 Evs
2434 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
Nikon D5
or the
Canon 1Ds MIII ,
including hyperfocal distance.
