Both Sony A7 III and Sony A99 have 24.0 MP resolution sensors but Sony A7 III's sensor is Full frame (35.8 x 23.8 mm ) and Sony A99's sensor is Full frame (35.8 x 23.8 mm ).
Since Sony A99'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 A7 III.
Below you can see the A7 III and A99 sensor size comparison.
Sony A7 III and Sony A99 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
Both Sony A7 III and Sony A99 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, A7 III has scored 96, 7 points higher than A99.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A7 III |
96 |
25.0 bits |
14.7 Evs |
3730 ISO |
Sony A99 |
89 |
25.0 bits |
14.0 Evs |
1555 ISO |