Canon 80D has a
24.0MP APS-C (22.5 x 15 mm ) sized CMOS sensor and features DIGIC 6 processor. On the other hand, Pentax K-3 III Mono has a
26.0MP APS-C (23 x 15.5 mm ) sized BSI-CMOS sensor and features PRIME V processor.
One other difference between these two cameras that is worth mentioning is that Pentax K-3 III Mono'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 80D and K-3 III Monochrome sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 80D and Pentax K-3 III Mono Cameras
Canon 80D and Pentax K-3 III Mono 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
Canon 80D
or the
Pentax K-3 III Mono ,
including hyperfocal distance.
