Both Sony A65 and Sony A6400 have 24.0 MP resolution sensors but Sony A65's sensor is APS-C (23.5 x 15.6 mm ) and Sony A6400's sensor is APS-C (23.5 x 15.6 mm ).
Since Sony A6400'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 A65.
Below you can see the A65 and A6400 sensor size comparison.
Sony A65 and Sony A6400 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 A65 and Sony A6400 sensors have been tested by DxO and the results show that A6400 has a better overall score of 83, 9 points higher compared to A65's score of 74.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A65 |
74 |
23.4 bits |
12.6 Evs |
717 ISO |
Sony A6400 |
83 |
24.0 bits |
13.6 Evs |
1431 ISO |