Olympus 7030 has a
14.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor and features TruePic III processor. On the other hand, Olympus VR-340 has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the 7030 and VR-340 sensor size comparison.
Olympus 7030 and Olympus VR-340 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.