Both Nikon D90 and Canon 450D 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 D90 and 450D sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D90 and Canon 450D Cameras
As seen above, Nikon D90 has a 1.1x Larger sensor area than Canon 450D. 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 Nikon D90 and Canon 450D 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, D90 has scored 73, 12 points higher than 450D.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon D90
73
22.7 bits
12.5 Evs
977 ISO
Canon 450D
61
21.9 bits
10.8 Evs
692 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
Nikon D90
or the
Canon 450D ,
including hyperfocal distance.
