Both Fujifilm F900EXR and Samsung WB850F have 16.0 MP resolution sensors but Fujifilm F900EXR's sensor is 1/2-inch (6.4 x 4.8 mm ) and Samsung WB850F's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Fujifilm F900EXR's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Samsung WB850F.
Below you can see the F900EXR and WB850F sensor size comparison.
Fujifilm F900EXR and Samsung WB850F have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.