Panasonic GX85 has a
16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features Venus Engine processor. On the other hand, Nikon D750 has a
24.0MP Full frame (35.9 x 24 mm ) sized CMOS sensor and features Expeed 4 processor.
Nikon D750's sensor provides 8MP more than Panasonic GX85'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.
Another difference between these two cameras is that Panasonic GX85's sensor lacks 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 GX85 and D750 sensor size comparison.
Sensor Size and Resolution Comparison image of Panasonic GX85 and Nikon D750 Cameras
As seen above, Nikon D750 has a 3.8x Larger sensor area than Panasonic GX85. 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 GX85 and Nikon D750 sensors have been tested by DxO and the results show that D750 has a better overall score of 93, 22 points higher compared to GX85's score of 71.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Panasonic GX85
71
22.9 bits
12.6 Evs
662 ISO
Nikon D750
93
24.8 bits
14.5 Evs
2956 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 GX85
or the
Nikon D750 ,
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.