Casio EX-Z800 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features Exilim Engine 5.0 processor. On the other hand, Fujifilm XQ2 has a
12.0MP 2/3' (8.8 x 6.6 mm ) sized CMOS X-TRANS II sensor and features EXR Processor II processor.
Below you can see the EX-Z800 and XQ2 sensor size comparison.
As seen above, Fujifilm XQ2 has a 2.1x Larger sensor area than Casio EX-Z800. 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.