Both Sony RX100 and Sony RX100 III have 20.0 MP resolution sensors but Sony RX100's sensor is 1-inch (13.2 x 8.8 mm ) and Sony RX100 III's sensor is 1″ (13.2 x 8.8 mm ).
Since Sony RX100 III'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 RX100 III sensor size comparison.
Sony RX100 and Sony RX100 III have the same sensor sizes so they will provide same level of control over the depth of field when used with 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 RX100 III sensors have been tested by DxO and the results show that RX100 III has a better overall score of 67, 1 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 RX100 III |
67 |
22.4 bits |
12.3 Evs |
495 ISO |