Sony A1 has a
50.0MP Full frame (35.9 x 24 mm ) sized Stacked CMOS sensor and features Dual Bionz XR processor. On the other hand, Sony A99 II has a
42.0MP Full frame (35.9 x 24 mm ) sized BSI-CMOS sensor and features Bionz X processor.
Sony A1's sensor provides 8MP more than Sony A99 II's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
One other difference between these two cameras that is worth mentioning is that Sony A99 II's sensor doesn't have an 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 A1 and A99 II sensor size comparison.
Sony A1 and Sony A99 II 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. On the other hand, since Sony A99 II has 18% larger pixel area (20.43µm2 vs 17.31µm2) compared to Sony A1, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.
DxOMark Sensor Scores
Both Sony A1 and Sony A99 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, A1 has scored 98, 6 points higher than A99 II.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony A1 |
98 |
25.9 bits |
14.5 Evs |
3163 ISO |
Sony A99 II |
92 |
25.4 bits |
13.4 Evs |
2317 ISO |