Samsung NX3000 has a
20.0MP APS-C (23.5 x 15.7 mm ) sized CMOS sensor . On the other hand, Nikon D7100 has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor .
One other difference between these two cameras that is worth mentioning is that Nikon D7100's sensor doesn't have an anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the NX3000 and D7100 sensor size comparison.
Sensor Size and Resolution Comparison image of Samsung NX3000 and Nikon D7100 Cameras
Samsung NX3000 and Nikon D7100 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
Samsung NX3000
or the
Nikon D7100 ,
including hyperfocal distance.
