Nikon L120 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Expeed C2 processor. On the other hand, Nikon L830 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor .
Below you can see the L120 and L830 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon L120 and Nikon L830 Cameras
Nikon L120 and Nikon L830 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 Nikon L120 has 14% larger pixel area compared to Nikon L830, it has potential to collect more light on pixel level hence 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
Nikon L120
or the
Nikon L830 ,
including hyperfocal distance.