Nikon D3100 has a 14.0MP APS-C (23.1 x 15.4 mm ) sized CMOS sensor and features Expeed 2 processor. On the other hand, Pentax K-50 has a 16.0MP APS-C (23.7 x 15.7 mm ) sized CMOS sensor and features PRIME M processor.
Below you can see the D3100 and K-50 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D3100 and Pentax K-50 Cameras
Nikon D3100 and Pentax K-50 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. Nikon D3100 and Pentax K-50 sensors have been tested by DxO and the results show that K-50 has a better overall score of 79, 12 points higher compared to D3100's score of 67.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Nikon D3100 |
67 |
22.5 bits |
11.3 Evs |
919 ISO |
Pentax K-50 |
79 |
23.7 bits |
13.0 Evs |
1120 ISO |