Both Sony H20 and Canon 400D have 10.0 MP resolution sensors but Sony H20's sensor is 1/2.3-inch (6.17 x 4.55 mm ) and Canon 400D's sensor is APS-C (22.2 x 14.8 mm ).
Since Canon 400D'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 Sony H20.
Below you can see the H20 and 400D sensor size comparison.
Sensor Size and Resolution Comparison image of Sony H20 and Canon 400D Cameras
As seen above, Canon 400D has a 11.7x Larger sensor area than Sony H20. 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.
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
Sony H20
or the
Canon 400D ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/2.3-inch versus APS-C),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.
