Olympus SZ-31MR iHS has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Dual TruePic V processor. On the other hand, Sony HX30V has a
18.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features BIONZ processor.
Below you can see the SZ-31MR iHS and HX30V sensor size comparison.
Sensor Size and Resolution Comparison image of Olympus SZ-31MR iHS and Sony HX30V Cameras
Olympus SZ-31MR iHS and Sony HX30V 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.
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
Olympus SZ-31MR iHS
or the
Sony HX30V ,
including hyperfocal distance.