Sony A7 III has a
24.0MP Full frame (35.8 x 23.8 mm ) sized BSI-CMOS sensor and features Bionz X processor. On the other hand, Sony A1 has a
50.0MP Full frame (35.9 x 24 mm ) sized Stacked CMOS sensor and features Dual Bionz XR processor.
Sony A1's sensor provides 26MP more than Sony A7 III'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 A7 III and A1 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A7 III and Sony A1 Cameras
Sony A7 III and Sony A1 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the 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 A7 III and Sony A1 sensors have been tested by DxO and the results show that A1 has a better overall score of 98, 2 points higher compared to A7 III's score of 96.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A7 III
96
25.0 bits
14.7 Evs
3730 ISO
Sony A1
98
25.9 bits
14.5 Evs
3163 ISO
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Sony A7 III
or the
Sony A1 ,
including hyperfocal distance.
