Both Sony RX1R and Sony A7 have Full frame sized 24.0 MP resolution sensors so sensor size and resolution is not a differentiator between these two cameras.
Another difference between these two cameras is that Sony RX1R's sensor lacks 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 RX1R and A7 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony RX1R and Sony A7 Cameras
Sony RX1R and Sony A7 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.
DxOMark Sensor Scores
Both Sony RX1R and Sony A7 sensors have been tested by DxoMark. DxoMark 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. Of the two cameras that we are comparing, RX1R has scored 91, 1 points higher than A7.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony RX1R
91
25.0 bits
13.6 Evs
2537 ISO
Sony A7
90
24.8 bits
14.2 Evs
2248 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 RX1R
or the
Sony A7 ,
including hyperfocal distance.
