Pentax WG-3 GPS has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor . On the other hand, Pentax P80 has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Prime processor.
Below you can see the WG-3 GPS and P80 sensor size comparison.
Pentax WG-3 GPS and Pentax P80 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 Pentax P80 has 32% larger pixel area (2.34µm2 vs 1.76µm2) compared to Pentax WG-3 GPS, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.