Nikon L20 has a
10.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor . On the other hand, Nikon P500 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Expeed C2 processor.
Below you can see the L20 and P500 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon L20 and Nikon P500 Cameras
Nikon L20 and Nikon P500 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 L20
or the
Nikon P500 ,
including hyperfocal distance.