Both Canon 10D and Canon 300D 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 300D sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 10D and Canon 300D Cameras
Canon 10D and Canon 300D have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture.
DxOMark Sensor Scores
Both Canon 10D and Canon 300D 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, 2 points higher than 300D.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon 10D
57
21.1 bits
10.9 Evs
571 ISO
Canon 300D
55
21.0 bits
10.8 Evs
544 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
Canon 300D ,
including hyperfocal distance.
