HDR Discussion Thread

[Geoff D]

Originally Posted by jrref

I'm not sure if this totally answers the question but hopefully it will put things into perspective.

HDR10 metadata is a single value of MaxCLL(max luminance) and MaxFALL(average luminance) for the entire video. What Sony and LG have done is to ignore this static metadata and generate max and avg luminance values frame by frame, generating Dynamic Metadata based on the content and the individual set's capabilities, which gives you a much better rendition of HDR10 content. It's very similar to what Samsung is trying to do with HDR10+ and since LG and Sony believe that they have the best implementation, it's doubtful that they will be early adaptors or ever offer HDR10+ since they are doing it their own way today. What's tied to the picture mode is the tone mapping. LG and Sony employ different tone mapping for each picture mode and since there is no tone mapping standard, manufacturers can do what ever they want and change their tone mapping at any time. Sony has already made tone mapping changes on the A1E since it was first offered.

Everyone has their own idea of what looks best because the tone mapping algorithm's differ between manufacturers and their picture modes which is generating all of the discussion.

I know. That's what I said: the Sony processing generates "dynamic" brightness but the level of highlight detail itself is still rigidly fixed to x level depending on what mode & settings you use, e.g. Custom is a hard clip to 1000 nits and Cinemas Home and Pro vary according to where their Contrast values are set, with both on the same settings then Pro is brighter but clips more aggressively while Home is darker but retains more highlight information. (Currently using Pro on the ZD9 to preserve more brightness in the mid ranges of the ST 2084 curve.)

Personally I think it's a bit disingenuous to even mention this in the same breath as actual dynamic systems because it's only halfway there. Adjusting luminance is absolutely better than nothing, granted (although when you've got almost 2000 nits on tap it becomes way less important) but for me dynamic tone mapping of highlights is the real juice.

[Robert Zohn]

I don't know if the Sony's dynamic HDR10 scheme on the Z9D works the same as the A1E, but Sony engineering told me they look at the entire luminance range of HDR10 content and they tone map the entire luminance range to the displays 10-bit luminance levels following very tightly to the EOTF curve.

Sony HDR TVs don’t use the static brightness metadata in HDR10 (MaxCLL, MaxFALL) they actually measured brightness frame by frame and generates dynamic metadata for HDR10 content across the entire contrast range.

This is also why the Sony TV’s APL (average picture level) is higher than the other TVs HDR when viewing HDR content (especially material mastered at 4000 nits). Sony X1Extreme equipped TVs only apply tone mapping (which reduces screen brightness and accuracy) when the brightness of the frame exceeds the TV set’s capabilities. When this occurs the display will gradually roll off the highest peak luminance in the specular highlights. Sony's dynamic approach to tone mapping of HDR10 content to the TVs peak luminance is applied to ensure HDR highlights and the entire range are properly displayed.

[Geoff D]

So why doesn't Sony's own 10,000 nit ramp (available on every one of their UHD discs) map the upper range down to what the TV can handle on the ZD9? Instead it just hard clips, with the level of clipping depending on what mode is selected. If I play something like Batman v Superman with its exceedingly bright HDR moments during the Doomsday battle then I can see different amounts of highlight detail between the selected modes.

I'll buy that it's doing something dynamically to the physical brightness output but not to the actual tone mapping of highlights, I haven't seen anything yet to support this and Vincent Teoh said the same thing in one of his vids.

[Robert Zohn]

Sony uses the SDR values (settings) from whatever mode you had your TV set to before the HDR metadata switches the TV into the HDR mode. Hence, a properly set-up (top professional calibrated) Cinema Pro mode would give you the HDR10 results you would like to see.

[Geoff D]

Originally Posted by Robert Zohn

Sony uses the SDR values (settings) from whatever mode you had your TV set to before the HDR metadata switches the TV into the HDR mode. Hence, a properly set-up (top professional calibrated) Cinema Pro mode would give you the HDR10 results you would like to see.

Do you really think I'm that much of a goober that I haven't changed my settings for HDR? I've profiled my colourimeter to the TV using a spectro (separate profile corrections for SDR and HDR) and used HCFR to gather readings, employing Ryan Masciola's rather excellent HDR10 patterns suite to measure & set greyscale, colour temperature, peak brightness, 2084 curve and so on. And I just don't see this "dynamic" tone mapping in action.

[Robert Zohn]

Thanks Geoff, just wanted to give as much information to be sure everyone knows how this works and what is required to get the best end results.

I did not mean to come off as if I was specifically speaking to just you and well appreciate your technical expertise.

[Geoff D]

No problem, I just want you know where I is coming from.

[KarmaNL]

I've got an appointment with a professional ISF-certified calibrator tonight, I'm very curious about the results and if it is really worth it.

[PeterTHX]

Originally Posted by Geoff D

The answer should be quite obvious if you look in most of the recent threads in the 4K movies forum...

"4KUHDBDmike"?

[Geoff D]

Hah, no. Trying going pre-DVD with the format and all should become clear...

[RockyIII]

Originally Posted by KarmaNL

I've got an appointment with a professional ISF-certified calibrator tonight, I'm very curious about the results and if it is really worth it.

Are you gettting ISF and HDR both calibrated?

[Penton-Man]

Update alert to a post from roughly a year ago….
https://forum.blu-ray.com/showthread...w#post12826906

From demo to commercial installation in the U.S. -
http://www.filmjournal.com/news/ymag...creen-us-debut

In due course, let’s hear some reviews from our members based in Austin.

[Penton-Man]

Originally Posted by Geoff D

The answer should be quite obvious if you look in most of the recent threads in the 4K movies forum...

Well if he lives anywhere near Bristol send him this link for the chance for free tickets…..
http://www.bbc.co.uk/showsandtours/s...planet_11oct17

[KarmaNL]

Originally Posted by RockyIII

Are you gettting ISF and HDR both calibrated?

Yes, and he did some slight tweaks to Dolby Vision and Game mode too.

[RockyIII]

Originally Posted by KarmaNL

Yes, and he did some slight tweaks to Dolby Vision and Game mode too.

So tell us all about it, mate

[KarmaNL]

He's sending me the before-and-after report, settings and results today.

White levels and colours were way out of whack, even on ISF Dark Mode. It looks a lot cleaner and easier on the eyes now after calibration.

[RockyIII]

Originally Posted by KarmaNL

He's sending me the before-and-after report, settings and results today.

White levels and colours were way out of whack, even on ISF Dark Mode. It looks a lot cleaner and easier on the eyes now after calibration.

Look forward to see that

[KarmaNL]

settings differ per panel though

[KarmaNL]

This is before and after calibration, starting point ISF Expert Dark Room mode.

As you can see the grayscale was way off

[RockyIII]

Originally Posted by KarmaNL

This is before and after calibration, starting point ISF Expert Dark Room mode.

As you can see the grayscale was way off

Yes I can tell. I also heard the 7 ootb are way more off than LG Oled from previous year