Both Panasonic FH27 and Fujifilm F800EXR have 16.0 MP resolution sensors but Panasonic FH27's sensor is 1/2.3-inch (6.08 x 4.56 mm ) and Fujifilm F800EXR's sensor is 1/2-inch (6.4 x 4.8 mm ).
Since Fujifilm F800EXR'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 Panasonic FH27.
Below you can see the FH27 and F800EXR sensor size comparison.
As seen above, Fujifilm F800EXR has a 1.1x Larger sensor area than Panasonic FH27. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.