I took the same photo with three different Lumix cameras and the exact same lens: G9, G90, GX80.
While taking the photos I kept the exposure constant (ISO 800, f2.8, 1/30)
After appliyng the “optical corrections only” preset I obtained results that differ in exposure and white balance:
The JPG images also differ but less:
What can be reason for these differences?
Different sensors, different firmware, etc
Absolutely. Using the same lens on three different camera models from the same company, even with the same settings, does not mean the resulting images will look even remotely the same. As an example, PhotoLab allows you to select a number of different Nikon profiles depending on which Nikon camera’s color profile you want to emulate. The results vary considerably from camera model to camera model. The same is true for all the other camera systems and models that PhotoLab supports. And, even those included profiles are only approximations.
What does the 17% and 18% mean? Different calibration of the light meter?
Maybe also variations in the actual shutter speed.
Also the actual exposure differs.
Interesting test, not surprising that differences exist, but I wouldn’t have expected such huge differences.