Canon R6 II has a
24.0MP Full frame (36 x 24 mm ) sized CMOS sensor and features Digic X processor. On the other hand, Canon R6 III has a
32.5MP Full frame (36 x 24 mm ) sized CMOS sensor and features Digic X processor.
Canon R6 III's sensor provides 8.5MP more than Canon R6 II'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 R6 II and R6 III sensor size comparison.
Sensor Size and Resolution Comparison image of Canon R6 II and Canon R6 III Cameras
Canon R6 II and Canon R6 III 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. On the other hand, since Canon R6 II has 42% larger pixel area compared to Canon R6 III, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.
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 R6 II
or the
Canon R6 III ,
including hyperfocal distance.