Both Sony A68 and Sony A7 have 24.0 MP resolution sensors but Sony A68's sensor is APS-C (23.5 x 15.6 mm ) and Sony A7's sensor is Full frame (35.8 x 23.9 mm ).
Since Sony A7'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 A68.
Below you can see the A68 and A7 sensor size comparison.
As seen above, Sony A7 has a 2.3x Larger sensor area than Sony A68. 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 A68 and Sony A7 sensors have been tested by DxO and the results show that A7 has a better overall score of 90, 11 points higher compared to A68's score of 79.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A68 |
79 |
24.1 bits |
13.5 Evs |
701 ISO |
Sony A7 |
90 |
24.8 bits |
14.2 Evs |
2248 ISO |