Working with HLG footage

[Cary Knoop]

Originally Posted by Paul Anderegg

This is HLG2100 timeline, ignore the previous ARIB reference in the export window. I don't know how to read these values, I am used to IRE and NIT from FCPX.
Paul

What happened to your blacks and shadows? For any night scene you must have close to 0 IRE blacks.

The way to Read the built-in Resovel parade and waveform is to ignore the numbers and consider 0 as black and 1023 as white. You can switch the scopes to use nits in HDR in the user preferences.

It looks like everything is raised. Highlights looked clipped, is this a straight out of camera video or in any way processed with LUTs or transcoded?

[Paul Anderegg]

You are looking at the raw clips on the timeline, no grading or correcting, only conformed as noted. Yeah, this is what HLG looks like in any way I touch it, like washed out log footage. Again...if I conform it to HDR10 (PQ) in FCPX, it comes out with great contrast, looking light a nice REC709 clip with colors that pop and highlights that peak at a real 1000nit. My HDR10 exports also include no grading, and look even worse on the SDR viewer, but on an HDR TV, they look correct.

Here is what the Resolve exported HLG2100 file looks like on my Sony HLG TV...and the TV did kick into HLG HDR when playing this file. The highlights are excessively low, like 100IRE low on my 1000nit TV at max backlight. :(

[Paul Anderegg]

Here is the raw HLG conformed to REC709 with no grading, which looks the same as if I had shot it in REC709 SDR as you can see...a bit noisier thanks to HLG though. If conformed to HDR10 (PQ), that streetlight would be like a laser beam shooting out of my TV set.

Paul

[Cary Knoop]

Originally Posted by Paul Anderegg

Yeah, this is what HLG looks like in any way I touch it, like washed out log footage.

Well that's a problem, did you enable some black level setup in your camera?

Note that the scopes in resolve work in float32, that means regardless if the video clip is video or data level the scope should show all values between black and white (super whites and blacks while not clipped are not shown on the Resovle scopes.

Could you share the mediainfo of the clip?
https://mediaarea.net/en/MediaInfo

[Paul Anderegg]

These clips are standard PXW-Z90 HLG/BT2020 with no other alterations to the picture profile settings.

Paul

[Cary Knoop]

Originally Posted by Paul Anderegg

These clips are standard PXW-Z90 HLG/BT2020 with no other alterations to the picture profile settings.

Paul

The problem is those scope readings have black start at 64 (10- bit) for HLG they should start at 0 in Resolve (I am aware that in other software this may be different) in case of a night shot.
You are absolutely sure they are not log shots?

[Paul Anderegg]

Confirmed, I don't ever shoot in log. I also find that he Z90 black level is always a few IRE above 0...if you close the iris and put the lens cap on, record a completely black clip, it will show above the 0IRE mark.

Paul

[Doug Jensen]

Every professional Sony camera I've ever used has elevated black levels at around +2 to +3 IRE. The first paint menu that needs to be changed when you take a new camera out of the box is to drop the master black level on a Sony camera so that the a waveform sits right at zero with the lens cap on. That one change makes all the difference.

[Cary Knoop]

Originally Posted by Doug Jensen

Every professional Sony camera I've ever used has elevated black levels at around +2 to +3 IRE. The first paint menu that needs to be changed when you take a new camera out of the box is to drop the master black level on a Sony camera so that the a waveform sits right at zero with the lens cap on. That one change makes all the difference.

Looking at the chart it is a lot higher than that for Paul's camera, black pretty much starts at 64 (10 bit levels). Now for software that scopes super whites and blacks that is exactly right but not for Resolve (and also for Premiere), both video and data levels are mapped the same way between 0 and 1023, super whites and blacks are not normally shown on the scopes.

It's rather strange if this came straight out of camera.

[Paul Anderegg]

Originally Posted by Doug Jensen

Every professional Sony camera I've ever used has elevated black levels at around +2 to +3 IRE. The first paint menu that needs to be changed when you take a new camera out of the box is to drop the master black level on a Sony camera so that the a waveform sits right at zero with the lens cap on. That one change makes all the difference.

Agreed Doug, I can CONFIRM this. ON my PMW320, and the PXWX320, the master black level must be set to -2 for the black to sit on the 0IRE line. Same for the X70/Z90/Z150...I tend to leave mine stock, because honestly, most viewers of our news don't calibrate their TV's, and run dynamic contrast, so they typically have monitors with way too low black levels. I think that's probably why Sony pushes the cameras out like this.

On my Z90, I found I need to set the master black to maximum -15 just to get shadows and blacks to not look elevated in daylight video. Even with gamma assist I find it hard to shoot in HLG, exposure in daylight is difficult to determine, not hard at night though. Zebras don't work in HLG...I mean they work, but not as expected or in any predictable manner...Doug?

Paul

[Tom Roper]

On the Resolve media page set the clip attribute data levels to 'video'. Black should now be at 0 IRE for a clip you shot in HLG.

[Tom Roper]

Originally Posted by Cary Knoop

Looking at the chart it is a lot higher than that for Paul's camera, black pretty much starts at 64 (10 bit levels).

Look at the RH side of the Resolve WFM. Blacks are at 0.
------------------------------------------------------------------------------------------

Paul,

1.) In Resolve Project Settings - Color Management:

- Color Science - DaVinci YRGB Color Managed
- Check the box for 'Use Separate Color Space and Gamma'
- Set Input Color Space to 'Bypass'
- Set Timeline Color Space to Rec.2020 - ARIB STD-B67 HLG
- Set Output to Rec.2020 - ARIB STD-B67 HLG

2.) On the media page:

- Right click on clip
- Set Attribute Data Level to 'Video'.
- Set Input Color Space to 'Bypass'

3.) On the render page - Advanced Settings:
- Set the Data Levels to 'Full'.

Proceed with the render.

[Doug Jensen]

Originally Posted by Paul Anderegg

Zebras don't work in HLG...I mean they work, but not as expected or in any predictable manner...Doug?

I have zero interest in HLG right now and consider it a complete waste of time, but with that said, I have no doubt that zebras could easily be used to set exposure.

[Cary Knoop]

Originally Posted by Tom Roper

Look at the RH side of the Resolve WFM. Blacks are at 0.

That is just some noise, the overall black level is way too high.

Originally Posted by Tom Roper

3.) On the render page - Advanced Settings:
- Set the Data Levels to 'Full'.

HLG requires video levels.

[Paul Anderegg]

Originally Posted by Tom Roper

Look at the RH side of the Resolve WFM. Blacks are at 0.
------------------------------------------------------------------------------------------

Paul,

1.) In Resolve Project Settings - Color Management:

- Color Science - DaVinci YRGB Color Managed
- Check the box for 'Use Separate Color Space and Gamma'
- Set Input Color Space to 'Bypass'
- Set Timeline Color Space to Rec.2020 - ARIB STD-B67 HLG
- Set Output to Rec.2020 - ARIB STD-B67 HLG

2.) On the media page:

- Right click on clip
- Set Attribute Data Level to 'Video'.
- Set Input Color Space to 'Bypass'

3.) On the render page - Advanced Settings:
- Set the Data Levels to 'Full'.

Proceed with the render.

OK, finished a quick low quality test clip using the Resolve settings you provided, looks much better. I found that on my PC spitting out normal SDR 8 bit RGB, that if I switch the TV to HLG mode, I get the same HDR picture as playing the file back through my TV via USB...that's nifty. So I might have a bit too much black crush? Here is the clip on YouTube, tell me what you think...it looked brighter when I shot it, and the shadows are brighter, but noisy, on the raw. I also included a side by side of a Resolve export FULL vs VIDEO levels on the render setting as the only difference. The YouTube version is FULL on render output.

Additionally, the settings you provided produce a file that plays back looking like a normal REC709 on an SDR screen, and HDR on HLG enabled monitor, so that is good. :-)

Paul

YouTube (Short URL)