FujiFilm S2800HD has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Casio EX-ZR700 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor and features EXILIM Engine HS 3 processor.
Below you can see the S2800HD and EX-ZR700 sensor size comparison.
FujiFilm S2800HD and Casio EX-ZR700 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 S2800HD has 15% larger pixel area compared to Casio EX-ZR700, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.