Both Canon 1100D and Pentax K-x 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 K-x sensor size comparison.
As seen above, Pentax K-x 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 Pentax K-x sensors have been tested by DxO and the results show that K-x has a better overall score of 72, 10 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 |
Pentax K-x |
72 |
22.8 bits |
12.5 Evs |
811 ISO |