Both Canon 350D and Nikon L21 have 8.0 MP resolution sensors but Canon 350D's sensor is APS-C (22.2 x 14.8 mm ) and Nikon L21's sensor is 1/2.3-inch (6.08 x 4.56 mm ).
Since Canon 350D'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 Nikon L21.
Below you can see the 350D and L21 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 350D and Nikon L21 Cameras
As seen above, Canon 350D has a 11.9x Larger sensor area than Nikon L21. 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
Canon 350D
or the
Nikon L21 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-C versus 1/2.3-inch),
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.
