Both Canon SD970 IS and Nikon D2Xs have 12.0 MP resolution sensors but Canon SD970 IS's sensor is 1/2.3-inch (6.17 x 4.55 mm ) and Nikon D2Xs's sensor is APS-C (23.7 x 15.7 mm ).
Since Nikon D2Xs'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 SD970 IS.
Below you can see the SD970 IS and D2Xs sensor size comparison.
Sensor Size and Resolution Comparison image of Canon SD970 IS and Nikon D2Xs Cameras
As seen above, Nikon D2Xs has a 13.3x Larger sensor area than Canon SD970 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
Canon SD970 IS
or the
Nikon D2Xs ,
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.
