[timstephens24]

Hmm - suspect RGB to YCbCr conversions (unless your TV is doing different things in RGB Full and YCbCr - Limited? ) I'd expect ITU 709 RGB to YCbCr to be used - not Rec 2020 - for HD content...

I'm pretty sure on the Shield that 4k@60/59 is using Rec 2020, while at all the other resolutions/frame rates is using Rec 709. I do wonder what 4k@60/59 without HDCP 2.2 active would be, but not sure how I would test that, maybe hook up an old HDMI cable?

Your point is based on two different greens I guess? (Though there is also some nasty edge enhancement on the 1080p stuff as if sharpness is being added on output or in the display - which will mask detail...)

Yeah, except it's not just the greens, but that was the easiest to show. I noticed the edge enhancement too, and I'm pretty sure that's all the Shield. Not sure how to fix that, since I don't use any upconverting on my receiver or edge enhancements/options on the TV.

The other issue to remember is that 4:2:0 YCbCr has 1/4 the chroma resolution of 4:4:4 RGB so UI details may show chroma-smearing on fine detail - though this doesn't have impact on video which in the consumer level is universally 4:2:0 (TV, DVD, Blu-ray etc.)

Yeah I looked up the difference after I noticed my Apple TV 4, NUC, and Samsung UBD-K8500 were all outputting YCbCr 4:4:4. The only thing with YCbCr 4:2:0 is the Shield @ 4k 59/60Hz, so I'm guessing that's the issue. I guess I'll see if I can put in something with NVIDIA.