Nikon Z9 has a
46.0MP Full frame (35.9 x 23.9 mm ) sized Stacked CMOS sensor and features Expeed 7 processor. On the other hand, Nikon Z6 III has a
24.0MP Full frame (35.9 x 23.9 mm ) sized Partially-Stacked CMOS sensor and features Expeed 7 processor.
Nikon Z9's sensor provides 22MP more than Nikon Z6 III'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 Z9 and Z6 Mark III sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon Z9 and Nikon Z6 III Cameras
Nikon Z9 and Nikon Z6 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 Nikon Z6 III has 86% larger pixel area (35.25µm 2 vs 18.88µm 2 ) compared to Nikon Z9, 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
Nikon Z9
or the
Nikon Z6 III ,
including hyperfocal distance.
