HDR 3D LUT's

I have issues trying to generate a 3D LUT for HDR.
No matter what setting I try it always comes out wrong.

I'm using a Pgen on a Sony Bravia 8 II.

I tried calibrated TV in PQ mode with tone map off.
And tried in SDR mode for a SDR to HDR conversion..

You cannot create a profile for any consumer Sony TV in HDR.

The TV is responsible for that, ColourSpace can profile professional monitors in 3D LUT HDR for over a decade already in professional area.

However, you can upload the BCS measurement file, the 3D LUT file you generated, and the verification BCS file.

Which method do you use to load the 3D LUT file? Do you use software or a hardware LUT box?

You 'can' generate any LUT for any display.
However, if the display is already in HDR mode there will be issues.
For example, can you disable Tone Mapping?
If not, there really will be a lot of issues.
If you can, using the HDR Guide for a display pre-set to PQ HDR will provide the info needed.
But, how stable is the displays?
Most consumer HDR displays are very unstable.
So you will need a lot of Stabilisation Patch time, as well as Drift to see what is going on.
And as no display can cover Rec2020, if you cannot set the display to native gamut you will likely need to use a Reduced Gamut patch set.

Basically, there are always ways to perform LUT calibration.
But you will need to understand the underlying issues, and how to overcome them.

Steve

I'm using a Black Magic Micro Converter & BMD Decklink for output

I guess the best method is to LUT it's SDR mode. To not having any Tone Mapping.

It's SDR Mode can hit a peak of 2,300 nits. But when I try to convert gamma 2.2 to PQ, it doesn't come out right. Im also able to use the full Gamut capabilities of the display in SDR mode.

If you are profiling in a power law EOTF with high brightness and native gamut, then there would be no real issue with calibrating to PQ HDR - unless the display is unstable.
You will need to post the profile to have it assessed.

Steve

Steve
I did a quick verify of the grayscale after measureming 17^3 patches and generating a LUT.
Near black/shadows always comes out extremly green in white balance.

Attached file: 17^3 Characterization

Attached file: Used to generate LUT

Attached file: Quck Verify of Grayscale

If you take the 17^3 profile, and map it to itself, you can see the TV has a lot of issues.
(A good display will map to itself well.)
Even looking at the EOTF targeting a standard colour space, you can see the TV has roll-off in the highlights in Blue, as well as a really bad blue EOTF.
The RGB Separation graph shows the issue too.
The RGB Balance graph is really weird because of this issue.
And then when you look at Drift, you can see the TV starts cool, and ends neutral/warm, and is unstable throughout.

And as it is a WOLED (no, it isn't!), it would likely be better to use a patch set that reduces the number of volumetric patches in the highlight.
Or keep things simple, and just use a Quick Profile Grey Ramp RGB Large (or your own patch set based on that.)

But, a full volumetric profile can be used, if you fix the stability issues, and the bad blue problem.

Steve

The TV is a QD-OLED

Bravia 8 mark 2

What's TB?

And what would be the best method for handling blue?

I could increase black insertion time to 10 seconds for cool down. What else can be done?

Oh, wow - then is has some real issues!
Far more than I thought...
I didn't bother checking the screen type.
But it is showing some real issues in the highlights.

TB was a typo - edited.

Steve

The ability to disable dynamic tone mapping does not mean that there is no processing occurring within the TV.

Sony still applies gamut mapping, and it has long been known that they experience significant volumetric errors.

You can use a 3D LUT for HDR when the panel is stable and gamut mapping is turned off, allowing the TV or monitor to display the native gamut without any processing.

For instance, the LG EP OLED can provide the native gamut in PQ format, and it can be profiled for HDR:

https://liftgammagain.com/forum/index.php?threads/lg-32-ep950-true-rgb-oled-calibration.16695/post-162842

Even if you find a consumer TV that supports HDR with a 3D LUT, you must use fixed HDR10 metadata for all movies.

This means you'll need a device like HDFury to manage fixed metadata that corresponds to the mastering monitor details.

Additionally, you must ignore the actual movie metadata, as the TV will alter the PQ shape with different metadata, rendering your calibration ineffective.

This is why I've previously mentioned that you cannot profile any consumer Sony TV for HDR due to numerous issues.

I know Ted doesn't like this, but you can indeed do 3D LUT calibration.
You will need to find the correct pre-calibration settings to remove the blue gamma issue, etc.
And if there are still gamut mapping issue, then a Reduced Gamut Patch set may be required.

Basically, there are always solution with ColourSpace.
You just need to define what the issues are, and how to overcome them.

But, for a QD-OLED that pre-calibration profile is bloody awful...

Steve

I guess the reason why it's awful it's because i'm using the displays vivid mode. It's the only mode that has SDR brightness unlocked up to 2500 nits. Other modes have it capped.

The 800 nits profile I uploaded was just for a test run without pushing the panel too hard.

I did another test run, this time up to 2500 nits. Turning off all the processing I can. And I was able to figure out that thr clipping was because the default contrast setting was too much. I had to lower it from 90 to 70, to prevent clipping in Vivid mode.

Which gave me a peak of 1600 nits. I also increased stabilization patch time to 10 seconds. But the test run was another failure.

As 'Vivid' mode is not the native colour space of the TV it will likely always cause issues.
You 'may' get better results with a Reduced Gamut patch set approach, if you can tame instability.

Steve