Canon 20D has a
8.0MP APS-C (22.5 x 15 mm ) sized CMOS sensor . On the other hand, Canon 400D has a
10.0MP APS-C (22.2 x 14.8 mm ) sized CMOS sensor .
Below you can see the 20D and 400D sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 20D and Canon 400D Cameras
Canon 20D and Canon 400D have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.
DxOMark Sensor Scores
At Camera Decision, we also look at Dxo Mark sensors when available as we think it is a good indicator of image quality.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon 20D
62
21.9 bits
11.0 Evs
721 ISO
Canon 400D
62
22.1 bits
11.0 Evs
664 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 20D
or the
Canon 400D ,
including hyperfocal distance.
