Samsung NX20 has a
20.0MP APS-C (23.5 x 15.7 mm ) sized CMOS sensor . On the other hand, Sony A7S III has a
12.0MP Full frame (35.6 x 23.8 mm ) sized BSI-CMOS sensor and features Bionz XR processor.
Samsung NX20's sensor provides 8MP more than Sony A7S III'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 NX20 and A7S III sensor size comparison.
As seen above, Sony A7S III has a 2.3x Larger sensor area than Samsung NX20. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.
DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Samsung NX20 and Sony A7S III sensors have been tested by DxO and the results show that A7S III has a better overall score of 85, 10 points higher compared to NX20's score of 75.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Samsung NX20 |
75 |
23.4 bits |
12.9 Evs |
785 ISO |
Sony A7S III |
85 |
24.2 bits |
13.4 Evs |
3900 ISO |