Both Nikon D40X and Canon SX120 IS have 10.0 MP resolution sensors but Nikon D40X's sensor is APS-C (23.7 x 15.6 mm ) and Canon SX120 IS's sensor is 1/2.5-inch (5.744 x 4.308 mm ).
Since Nikon D40X'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 SX120 IS.
Below you can see the D40X and SX120 IS sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D40X and Canon SX120 IS Cameras
As seen above, Nikon D40X has a 14.9x Larger sensor area than Canon SX120 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
Nikon D40X
or the
Canon SX120 IS ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-C versus 1/2.5-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.
