Panasonic G1 has a
12.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor . On the other hand, Nikon Z9 has a
46.0MP Full frame (35.9 x 23.9 mm ) sized Stacked CMOS sensor and features Expeed 7 processor.
Nikon Z9's sensor provides 34MP more than Panasonic G1'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 G1 and Z9 sensor size comparison.
Sensor Size and Resolution Comparison image of Panasonic G1 and Nikon Z9 Cameras
As seen above, Nikon Z9 has a 3.8x Larger sensor area than Panasonic G1. 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.
DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Panasonic G1 and Nikon Z9 sensors have been tested by DxO and the results show that Z9 has a better overall score of 98, 45 points higher compared to G1's score of 53.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Panasonic G1
53
21.1 bits
10.3 Evs
463 ISO
Nikon Z9
98
26.3 bits
14.4 Evs
2451 ISO
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
Panasonic G1
or the
Nikon Z9 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Four Thirds versus Full frame),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.