Canon R7 has a
33.0MP APS-C (22.2 x 14.8 mm ) sized CMOS sensor and features Digic X processor. On the other hand, Sigma Quattro has a
29.0MP APS-C (23.5 x 15.6 mm ) sized CMOS (Foveon X3) sensor and features Dual TRUE III processor.
One other difference between these two cameras that is worth mentioning is that Sigma Quattro'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 R7 and Quattro sensor size comparison.
Sensor Size and Resolution Comparison image of Canon R7 and Sigma Quattro Cameras
As seen above, Sigma Quattro has a 1.1x Larger sensor area than Canon R7. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in 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
Canon R7
or the
Sigma Quattro ,
including hyperfocal distance.
