Originally Posted by zeonstar
Hello again. Thanks for the further information. I must admit I am not quite following all of this, but I am trying. Please bear with me. When you say a "steeper slope" what do you mean? Using my own screenshots as an example, maybe they can help me understand better. On the image with both mappers on, I clearly see more flesh tones on the face, but there are less bright highlights. Which makes me wonder...which one is right? Perhaps there is no right answer? It's just...preference?
You can only get the exactly "right" picture if you have enough nits (say 4000 nits). The dotted white line in the graph below is a standard ST.2084 PQ curve. It shows what would happen on a 1000-nit TV without tone mapping (see yellow line). All inputs above 75% are hard-clipped , i.e., displaying as pure white with no details.
The yellow line in the second graph shows the "standard" tone mapping based on ST.2390. In essence it compresses the luminance range from 4000 to 1000 in order to "fit" everything (note the expanded scale for clarity). The dotted white line is an alternate tone mapping with steeper slope near the top. It shows "more" highlight details by providing a greater differentiation between 85% and 90% compared with the yellow line, but all the highlights are dimmer.
What I'm trying to say is that, it's preferred to do all such adjustments in one device (the UB820 provides controls for adjusting the tone mapping). If you do tone mapping in two independent devices, you cannot predict what the overall effect will be.
Is this the same as using the HDR Optimizer on the player or something different?
It's related. HDR Optimizer varies the tone mapping depending on the source material.
When you say ALL, do you mean mapping down to what the TV can handle, nits wise? (As opposed to just mapping down to 1000 nits which is still higher than my TV handles.)
Yes. If your TV can handle what the player maps to, then it does not need to perform any tone mapping.
If something is mapped to 1000 and my TV optimizer is off, anyhting between my TVs 800 nits (or whatever it is) and the 1000 nits of the disc is just lost correct?
No, it won't be "lost". Your TV will be tone mapping from 1000 down to 800 nits, unless you turn off it’s tone mapping in which case the extreme highlights will be clipped.
A user mentioned something to me yesterday I had never heard before. He said the UB820 can actually map down to what your TV can handle (Because the TV tells the player what it can handle) and not just to 1000 nits as I previous thought.
You can "tell" the UB820 what your TV's peak luminance is. However, there are only a few presets to choose from.
Is that what are you are saying happens by using SDR2020? SDR in this case doesn't stand for Standard Dynamic Range, does it?
SDR does stand for Standard Dynamic Range, but it's misleading in this case. You are essentially telling the UB820 to "handle" all the HDR functions, so that the TV doesn't need to worry about it.
At first I thought using 2 was definitely not the way to go, but perhaps it isn't as clear as I first though.
As I mentioned, it's not "wrong" to do it, but the results are not well-defined. If, as you stated earlier, “I like playing my content as pure as possible, without any enhancements or changes”, then double tone mapping will not give you that.