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, Ricoh GXR P10 28-300mm has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Smooth Imaging Engine IV processor.
Below you can see the EX-Z800 and GXR P10 28-300mm F3.5-5.6 VC sensor size comparison.
Casio EX-Z800 and Ricoh GXR P10 28-300mm 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.