Both Canon 10D and Nikon D40 have APS-C sized 6.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the 10D and D40 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 10D and Nikon D40 Cameras
Canon 10D and Nikon D40 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 Canon 10D and Nikon D40 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, 10D has scored 57, 1 points higher than D40.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon 10D
57
21.1 bits
10.9 Evs
571 ISO
Nikon D40
56
21.0 bits
11.0 Evs
561 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 10D
or the
Nikon D40 ,
including hyperfocal distance.
