Nikon L820 has a
16.0MP 1/2.3-inch (6.16 x 4.62 mm ) sized BSI-CMOS sensor . On the other hand, Canon SX720 HS has a
20.3MP 1/2.3 (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features DIGIC 6 processor.
Canon SX720 HS's sensor provides 4.3MP more than Nikon L820's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the L820 and SX720 HS sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon L820 and Canon SX720 HS Cameras
Nikon L820 and Canon SX720 HS have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the 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 L820
or the
Canon SX720 HS ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/2.3-inch versus 1/2.3),
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.