Fujifilm F500 EXR has a
16.0MP 1/2-inch (6.4 x 4.8 mm ) sized EXRCMOS sensor and features EXR processor. On the other hand, FujiFilm F300EXR has a
12.0MP 1/2-inch (6.4 x 4.8 mm ) sized CCD sensor and features EXR processor.
Below you can see the F500 EXR and F300EXR sensor size comparison.
Fujifilm F500 EXR and FujiFilm F300EXR 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 F300EXR has 32% larger pixel area (2.56µm2 vs 1.93µm2) compared to Fujifilm F500 EXR, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.