Sony A9 III has a
24.6MP Full frame (35.6 x 23.8 mm ) sized Global Shutter sensor and features BIONZ XR processor. On the other hand, Leica SL2-S has a
24.0MP Full frame (36 x 24 mm ) sized BSI-CMOS sensor and features Maestro III processor.
Another similarity between these two cameras is that both Leica SL2-S and Sony A9 III sensors lack anti-alias (Low-Pass) filters. 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 A9 Mark III and SL2-S sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A9 III and Leica SL2-S Cameras
Sony A9 III and Leica SL2-S 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.
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 A9 III
or the
Leica SL2-S ,
including hyperfocal distance.
