Pentax WG-3 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor . On the other hand, FujiFilm JZ500 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the WG-3 and JZ500 sensor size comparison.
Pentax WG-3 and FujiFilm JZ500 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 FujiFilm JZ500 has 14% larger pixel area (2.01µm2 vs 1.76µm2) compared to Pentax WG-3, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.