Originally Posted by MrRobotoPlus
Why everybody is complaining about the ATV 4K 1080p upscaling? I own a ks8000 which is known for its very good upscaler and i don't notice any differences between the two. Am I missing something?
Originally Posted by ggw2000
Have to agree with you, I own a Sony XBR and have tested "scaling" both ways with the Shield TV and the ATV 4K. There is little to no difference in PQ. There is very little content on itunes that is actually HDR. I just set the unit to output 4KSDR 60Hz and get on with life. This whole fiasco (even tho apple is wrong) is way overblown in my estimation.
Note to "Austinjerry"- keep the ATV as I believe it will give you everything you need in the long run (Amazon) plus cheaper movies in itunes that can not be had elsewhere. PS: Been awhile since the 65X900A thread huh
Glad you found a setup that works for you. I bought the ATV5 in order to watch HDR and WCG content whenever available, and that means about half the content I watch on it. Leaving HDR off completely defeats the value of the device. I'd get the more stable cheaper performance from the ATV4 (not 4k). In fact, I use one on my non HDR set and it's awesome.
For people who want to watch HDR -- which I would think it most people who buy the ATV5, otherwise why spend the money? -- this upscaling issue is not about upscaling to 2160p. The larger problem is that it is also transforming SDR to HDR and to a different color space.
In theory, this COULD work okay on professional grade equipment:
SDR in -> inverse 1886 EOTF -> 3x3 matrix conversion from Rec. 709 to Rec. 2020 -> relative to absolute luminance scaling -> 2084 EOTF -> HDR out
In practice, there are lot of ways this can fail.
First they may be trying to enhance or goose up the SDR content, like the "feature" on some TV sets, meaning you never get to see what the content creators intended.
But let's assume they are trying to maintain the original content within this larger container.
This relies on assumptions about how SDR content is mastered (which are usually true).
The trouble is, even if all that is true, the way many (or even most) TV's handle HDR these days is not perfect.
These days, even cheap TV's can track 709 and SDR (1886) perfectly, but many fudge on how well they track HDR 2084 and rec 2020. Should our TV's get it right? Sure. And one day they may and then the ATK4K approach of up converting everything could work better.
For now, in the real world, Apple's approach means SDR content (unconverted by Apple for all displays) will look less accurate than simply feeding SDR 1886 and rec709 color to the same display.
And I think this will be the case for several years to come. Flat panels may get good enough to mitigate this in a few years.
In addition to not tracking HDR as well as SDR, they also compromise by doing things like maxing out their backlight and contrast when getting an HDR signal, meaning for this upconverted content, which doesn't need the max lumens, the black floor is raised and the effective contrast of SDR material is also greatly diminished when watching it as upconverted content.
You paid for those great black levels and Apple has taken them away.
So it's a trifecta: color is wrong, gamma is wrong, and black levels are raised & contrast is compromised.
And for projector owners it's even worse, since you are probably burning up your lamp in high lamp mode in HDR mode, unnecessarily with SDR content.
Originally Posted by AustinJerry
I think you are missing the most important point of my post. Sure, it is acceptable to let the AppleTV 4K upscale 1080p to 4K SDR, especially if you think it does as good a job as the display. But what is not OK is if the ATV outputs non-HDR content as if it were HDR, using BT.2020. The ATV should detect whether the video stream is HDR or not, and output the correct signal accordingly. If you want to be responsible for manaually changing the video settings in the ATV depending on whether the source is HDR or not, then you are more tolerable of a serious flaw than I am.
Originally Posted by ggw2000
As I noted- Apple is wrong in their implementation
. This may change with the amount of flak they are getting..
Yep the workaround is manually adjusting settings each time you watch a different kind of content. That works, but it's getting old. I too hope Apple gives us the option to pass through native content.