Sony FX3 has a
12.0MP Full frame (35.6 x 23.8 mm ) sized BSI-CMOS sensor and features Bionz XR processor. On the other hand, Sony A9 has a
24.0MP Full frame (35.6 x 23.8 mm ) sized Stacked BSI-CMOS sensor and features BIONZ X processor.
Sony A9's sensor provides 12MP more than Sony FX3'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.
Below you can see the FX3 and A9 sensor size comparison.
Sony FX3 and Sony A9 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 FX3 has 99% larger pixel area compared to Sony A9, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.
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 FX3 and Sony A9 sensors have been tested by DxO and the results show that A9 has a better overall score of 92, 7 points higher compared to FX3's score of 85.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Sony FX3 |
85 |
24.2 bits |
13.4 Evs |
3900 ISO |
Sony A9 |
92 |
24.9 bits |
13.3 Evs |
3517 ISO |