Canon EOS C80 has a
19.0MP Full frame (36 x 24 mm ) sized BSI Stacked CMOS sensor . On the other hand, Canon R1 has a
24.0MP Full frame (36 x 24 mm ) sized Stacked CMOS sensor and features Digic X processor.
Canon R1's sensor provides 5MP more than Canon EOS C80'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 C80 and R1 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon EOS C80 and Canon R1 Cameras
Canon EOS C80 and Canon R1 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 R1 has 12% larger pixel area (36.00µm 2 vs 32.00µm 2 ) compared to Canon EOS C80, it has larger pixel area to collect light hence potential to 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 EOS C80
or the
Canon R1 ,
including hyperfocal distance.