Canon D30 has a
3.0MP APS-C (22.7 x 15.1 mm ) sized CMOS sensor . On the other hand, Samsung NX20 has a
20.0MP APS-C (23.5 x 15.7 mm ) sized CMOS sensor .
Samsung NX20's sensor provides 17MP more than Canon D30'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 D30 and NX20 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon D30 and Samsung NX20 Cameras
Canon D30 and Samsung NX20 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.
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
Canon D30
or the
Samsung NX20 ,
including hyperfocal distance.
