Both Canon 1000D and Sony G3 have 10.0 MP resolution sensors but Canon 1000D's sensor is APS-C (22.2 x 14.8 mm ) and Sony G3's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Canon 1000D'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 G3.
Below you can see the 1000D and G3 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 1000D and Sony G3 Cameras
As seen above, Canon 1000D has a 11.7x Larger sensor area than Sony G3. 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 1000D
or the
Sony G3 ,
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.
