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, Samsung ST6500 has a
16.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Below you can see the EX-Z800 and ST6500 sensor size comparison.
Sensor Size and Resolution Comparison image of Casio EX-Z800 and Samsung ST6500 Cameras
Casio EX-Z800 and Samsung ST6500 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.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Casio EX-Z800
or the
Samsung ST6500 ,
including hyperfocal distance.