Olympus TG-310 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features TruePic III+ processor. On the other hand, Olympus TG-630 iHS has a
12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CMOS sensor .
Below you can see the TG-310 and TG-630 iHS sensor size comparison.
Sensor Size and Resolution Comparison image of Olympus TG-310 and Olympus TG-630 iHS Cameras
Olympus TG-310 and Olympus TG-630 iHS 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 TG-310
or the
Olympus TG-630 iHS ,
including hyperfocal distance.