Both Canon SX260 HS and Canon N have 1/2.3-inch sized 12.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the SX260 HS and N sensor size comparison.
Sensor Size and Resolution Comparison image of Canon SX260 HS and Canon N Cameras
Canon SX260 HS and Canon N have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Canon N has 33% larger pixel area (3.12µm 2 vs 2.34µm 2 ) compared to Canon SX260 HS, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.
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 SX260 HS
or the
Canon N ,
including hyperfocal distance.
