Canon 70D has a
20.0MP APS-C (22.5 x 15 mm ) sized CMOS sensor and features Digic 5+ processor. On the other hand, Samsung NX500 has a
28.0MP APS-C (23.5 x 15.7 mm ) sized BSI-CMOS sensor and features DRIMe 5 processor.
Samsung NX500's sensor provides 8MP more than Canon 70D'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.
One other difference between these two cameras that is worth mentioning is that Samsung NX500'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 70D and NX500 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 70D and Samsung NX500 Cameras
Canon 70D and Samsung NX500 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.
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. Canon 70D and Samsung NX500 sensors have been tested by DxO and the results show that NX500 has a better overall score of 87, 19 points higher compared to 70D's score of 68.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon 70D
68
22.5 bits
11.6 Evs
926 ISO
Samsung NX500
87
24.8 bits
13.9 Evs
1379 ISO
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 70D
or the
Samsung NX500 ,
including hyperfocal distance.
