Sony HX50V has a
20.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor . On the other hand, Samsung SL720 has a
12.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor .
Sony HX50V's sensor provides 8MP more than Samsung SL720's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the HX50V and SL720 sensor size comparison.
Sony HX50V and Samsung SL720 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.