Olympus FE-5020 has a
12.0MP 1/2.3-inch (6.17 x 4.55 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 FE-5020 and VR-340 sensor size comparison.
Olympus FE-5020 and Olympus VR-340 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. On the other hand, since Olympus FE-5020 has 35% larger pixel area compared to Olympus VR-340, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.