Both Canon 1100D and Nikon D300S have APS-C sized 12.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the 1100D and D300S sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 1100D and Nikon D300S Cameras
As seen above, Nikon D300S has a 1.1x Larger sensor area than Canon 1100D. 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 1100D and Nikon D300S sensors have been tested by DxO and the results show that D300S has a better overall score of 70, 8 points higher compared to 1100D's score of 62.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon 1100D
62
21.9 bits
11.0 Evs
755 ISO
Nikon D300S
70
22.5 bits
12.2 Evs
787 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 1100D
or the
Nikon D300S ,
including hyperfocal distance.
