Originally Posted by cjeman
All through the beta processes for the Shield 7.2.3, the UHD60 showed it shifting between Cinema and HDR (with flagging) when playing a specific source. Manually shifting the UHD60 between Cinema & HDR shows no appreciable differences on any source. So, I agree with your point.
Bottom line is that the UHD60 and Shield TV are a great combination.
I have now both an Apple TV 4k and Shield 4k and observed some notable differences viewing the same content:
1. The shiled runs in 4k/60Hz SDR in the menus and SDR content, and the colour space switches in the background when HDR content is played. The UHD 60 colour gradient visibly shifts as it does so, but there is no change in the signal so the UHD60 doesn't notice anything happening, but the Auto HDR processing does its job seamlessly. From here I manually swap to HDR picture settings to view content.
2. the Apple TV can run in HDR mode 4k/50/60Hz full time and re-processes SDR content to HDR signal, but since it is recommended to have match range and refresh rate on, you are better off setting the ATV in SDR mode full time and it will switch to HDR signal at the same time it switches to a difference refresh rate (like 24Hz). If the content to be watched is 25Hz, then the ATV will stay at 50Hz (in my region) and frame double.
3. The ATV will show the HDR logo mid stream if the content is present
4, The UHD picture settings are unqiue per input, so if you make all your changes to 50Hz (or 60Hz) input, when the ATV switches to 24Hz the picture settings are reset, you have to set them all up again (the 1st time) and then it will remember. So if you have Cinema set for the menus, and watch an SDR movie in 24Hz you have to reset all you Cinema presets to you liking as its a different profile to the 50Hz one (and different again for 60Hz).
If you want the UHD60 to show the exact same personal picture settings for each present (Cinema, HDR etc) you have to set them for each input (24/50/60) separately, HDr has no bearing on the switch, just the input refresh.