Sony HX20V has a
18.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features BIONZ processor. On the other hand, Samsung WB750 has a
13.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor .
Sony HX20V's sensor provides 5MP more than Samsung WB750'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 HX20V and WB750 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony HX20V and Samsung WB750 Cameras
Sony HX20V and Samsung WB750 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 Samsung WB750 has 42% larger pixel area (2.23µm 2 vs 1.56µm 2 ) compared to Sony HX20V, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Sony HX20V
or the
Samsung WB750 ,
including hyperfocal distance.