Diffraction is an optical effect which limits the total resolution of a camera — no matter how many megapixels the camera sensor has. It happens because light begins to disperse or “diffract” when passing through the small opening that is the lens aperture. The smaller the aperture the greater the diffraction.
There have been a couple of reports online of a magenta colour cast appearing when G9 raw files are exposure lifted in Adobe Lightroom. I have to date not noticed this myself although I have to say I am not wholly convinced by Lightroom’s raw conversion of the G9 files. It may well be that I have not noticed this reported issue since I tend to ensure that I do not significantly under-expose images and therefore tend not to have lift exposure significantly in post processing.