Leica M Typ 240 has a
24.0MP Full frame (36 x 24 mm ) sized CMOS sensor . On the other hand, Sony A9 III has a
24.6MP Full frame (35.6 x 23.8 mm ) sized Global Shutter sensor and features BIONZ XR processor.
One other difference between these two cameras that is worth mentioning is that Sony A9 III'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 M Typ 240 and A9 Mark III sensor size comparison.
Sensor Size and Resolution Comparison image of Leica M Typ 240 and Sony A9 III Cameras
Leica M Typ 240 and Sony A9 III 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. Leica M Typ 240 and Sony A9 III sensors have been tested by DxO and the results show that A9 Mark III has a better overall score of 87, 3 points higher compared to M Typ 240's score of 84.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Leica M Typ 240
84
24.0 bits
13.3 Evs
1860 ISO
Sony A9 III
87
24.1 bits
13.0 Evs
3224 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
Leica M Typ 240
or the
Sony A9 III ,
including hyperfocal distance.
