Both Leica Q and Sony RX1 have Full frame sized 24.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Below you can see the Q Typ 116 and RX1 sensor size comparison.
Sensor Size and Resolution Comparison image of Leica Q and Sony RX1 Cameras
Leica Q and Sony RX1 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 Q and Sony RX1 sensors have been tested by DxO and the results show that RX1 has a better overall score of 93, 8 points higher compared to Q Typ 116's score of 85.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Leica Q
85
24.3 bits
12.7 Evs
2221 ISO
Sony RX1
93
25.1 bits
14.3 Evs
2534 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 Q
or the
Sony RX1 ,
including hyperfocal distance.