Both Sony A300 and Canon SD4000 IS have 10.0 MP resolution sensors but Sony A300's sensor is APS-C (23.6 x 15.8 mm ) and Canon SD4000 IS's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Sony A300'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 Canon SD4000 IS.
Below you can see the A300 and SD4000 IS sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A300 and Canon SD4000 IS Cameras
As seen above, Sony A300 has a 13.3x Larger sensor area than Canon SD4000 IS. 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 A300
or the
Canon SD4000 IS ,
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.
