I'm starting to get reports of a severe banding problem that seems to be related to the recent macOS 10.14.6 update which includes some (unknown) changes to ColorSync. I've duplicated this and what I'm seeing is that when a display profile has the r/g/bTRC "curv" tag encoded as a "simple gamma" value rather than an array of points (typically 256), then there can be a big luminance discontinuity between level RGB=0 and RGB=1 - depending on the gamma value. I'm using a simple grayscale test image in the Preview app. The canned "Adobe RGB (1998)" profile encodes the 2.2 gamma as a "simple gamma" and this issue is evident when selected as a display profile. However the "Generic RGB Profile" encodes gamma 1.8 this way also but the discontinuity isn't very obvious. So higher gamma values make this more obvious. Re-encoding the profile's response curve as an array of points instead of a single "simple gamma" value seems to avoid the issue. However it was perfectly OK in previous macOS versions. Is anyone else experiencing this issue? It looks like X-Rite encode their TRCs as an array of points regardless, so probably most people won't see it. Anyone at Apple aware of this? Thanks Will Hollingworth