Both Leica SL and Sony A77 II have 24.0 MP resolution sensors but Leica SL's sensor is Full frame (36 x 24 mm ) and Sony A77 II's sensor is APS-C (23.5 x 15.6 mm ).
Since Leica SL'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 A77 II.
Another difference between these two cameras is that Leica SL's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the SL and A77 II sensor size comparison.
As seen above, Leica SL has a 2.4x Larger sensor area than Sony A77 II. 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
Both Leica SL and Sony A77 II sensors have been tested by DxoMark. DxoMark 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. Of the two cameras that we are comparing, SL has scored 88, 6 points higher than A77 II.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Leica SL |
88 |
25.0 bits |
13.4 Evs |
1821 ISO |
Sony A77 II |
82 |
24.4 bits |
13.4 Evs |
1013 ISO |