Samsung WB30F has a
16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Sony W620 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features BIONZ processor.
Below you can see the WB30F and W620 sensor size comparison.
Samsung WB30F and Sony W620 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.