Both Canon 40D and Olympus E-450 have 10.0 MP resolution sensors but Canon 40D's sensor is APS-C (22.2 x 14.8 mm ) and Olympus E-450's sensor is Four Thirds (17.3 x 13 mm ).
Since Canon 40D's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Olympus E-450.
Below you can see the 40D and E-450 sensor size comparison.
As seen above, Canon 40D has a 1.5x Larger sensor area than Olympus E-450. 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
Both Canon 40D and Olympus E-450 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, 40D has scored 64, 8 points higher than E-450.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Canon 40D |
64 |
22.1 bits |
11.3 Evs |
703 ISO |
Olympus E-450 |
56 |
21.5 bits |
10.5 Evs |
512 ISO |