Sony H20 has a
10.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor . On the other hand, Sony H50 has a
9.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor .
Below you can see the H20 and H50 sensor size comparison.
Sony H20 and Sony H50 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 H50 has 11% larger pixel area (3.13µm2 vs 2.81µm2) compared to Sony H20, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.