Both Sony A7CR and Sigma fp L have Full frame sized 61.0 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 A7CR'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 A7CR and fp L sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A7CR and Sigma fp L Cameras
Sony A7CR and Sigma fp L 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 A7CR
or the
Sigma fp L ,
including hyperfocal distance.
