Sony A6600 has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz X processor. On the other hand, Canon M6 MII has a
33.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 8 processor.
Canon M6 MII's sensor provides 9MP more than Sony A6600's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the A6600 and M6 II sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A6600 and Canon M6 MII Cameras
As seen above, Sony A6600 has a 1.1x Larger sensor area than Canon M6 MII. 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
Sony A6600
or the
Canon M6 MII ,
including hyperfocal distance.