Sony W330 has a
14.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Nikon W300 has a
16.0MP 1/2.3 (6.17 x 4.55 mm ) sized sensor .
Below you can see the W330 and W300 sensor size comparison.
Sony W330 and Nikon W300 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 Sony W330 has 14% larger pixel area compared to Nikon W300, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.