Nikon P310 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor . On the other hand, Nikon P300 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 P310 and P300 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon P310 and Nikon P300 Cameras
Nikon P310 and Nikon P300 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 P300 has 32% larger pixel area (2.34µm 2 vs 1.76µm 2 ) compared to Nikon P310, 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
Nikon P310
or the
Nikon P300 ,
including hyperfocal distance.