Casio EX-Z550 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Samsung WB35F has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the EX-Z550 and WB35F sensor size comparison.
Casio EX-Z550 and Samsung WB35F 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 Casio EX-Z550 has 14% larger pixel area compared to Samsung WB35F, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.