Both Sony RX100 and Sony a5000 have 20.0 MP resolution sensors but Sony RX100's sensor is 1-inch (13.2 x 8.8 mm ) and Sony a5000's sensor is APS-C (23.2 x 15.4 mm ).
Since Sony a5000's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Sony RX100.
Below you can see the RX100 and a5000 sensor size comparison.
As seen above, Sony a5000 has a 3.1x Larger sensor area than Sony RX100. 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. Sony RX100 and Sony a5000 sensors have been tested by DxO and the results show that a5000 has a better overall score of 79, 13 points higher compared to RX100's score of 66.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony RX100 |
66 |
22.6 bits |
12.4 Evs |
390 ISO |
Sony a5000 |
79 |
23.8 bits |
13.0 Evs |
1089 ISO |