HDR Reference White

In my blog post detailing the color correction workflow for HDR10, a reader asked where reference white and 18% gray should fall on the waveform monitor, and I incorrectly answered 100 nits for reference white and in the 40s for 18% gray. While typical white levels presently used in PQ production range anywhere from 145 – 250 nits, it is recommended that HDR Reference White (diffuse white) be 200 nits while 18% gray should be 26 nits, as shown in the illustration below. In the end though, where the white point falls is a creative choice, not a law carved in stone!

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Rajesh Kumar says:

March 14, 2021 at 9:08 pm

Thank you so much for your courteous response.
( I had asked you that question in your previous blogpost 🙂 )

Looks like time for me to re-grade my BMPCC footage now.

Also here is a small video I did in HDR – https://youtu.be/JnmbNSEOWgk

It’s not super accurate… I just took all the old footage I had shot in BMPCC and Sony A6300 in RAW… and did simple Tone Mapping from BMD Film Gamma & Slog2 ( for Sony ) to HDR ST2084 spec ( I guess that’s why HDR PQ is… With Max Brightness set to 1000nit )

Before shooting most of the Clips in the video above.. I used to take a small 2-3sec clip of Color Check Passport Video…

So I guess I’ll try to re-adjust the clips based on the new Reference you provided for Diffused White and 18% Gray.

Again Thanks.
( In one of clips in the video above…it’s my Nephew and my sister in a high dynamic range … I do see I am reaching the limits of the original BMPCC .. )

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1. jonpais says:
  
  March 14, 2021 at 11:06 pm
  
  Looks like you had fun playing around with all that footage! I like the backlighting in the shot of your sister holding your nephew. 203 nits is the official number for HDR Reference White, which is why I shared a link to a paper in the blog post arguing why 200 nits should be the standard. But that’s nitpicking! 😂
  
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Rajesh Kumar says:

March 14, 2021 at 9:17 pm

Also, I am using LG CX OLED as a reference monitor.

I override the HDMI Signal using their secret ( not a secret anymore ) menu – 1113111

I set the Gamma to HDR ST2084 , Color to Rec 2020 and Mastering to 1000nits..

Hope what I am doing this correct..in terms of setting up the TV for mastering…

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