So, How Do We Calibrate Our TVs for HDR?

VHS Gamer

Active Member
I'm relatively familiar with SDR basic calibration, but how is HDR different from SDR calibration? It would be super helpful if this could be cleared up as I've not been using HDR at all under the assumption that there is no standard for it like SDR. Meaning, the moment we switch it on, we're not seeing what the director intended. So my questions are...

  • How is black level and white level set with HDR?
  • And Colour?
  • Is the Dynamic Range the same of 16-235 or 0-255? Or something else?

Basically, how is calibration of HDR different from SDR?
 

mmj

Active Member
I'm by no means an expert but as someone who has researched and dabbled in it I'll give this a go, anyone please correct me if I'm wrong.

Firstly, you will need a pattern generator that outputs HDR, you can achieve this using a modern graphics card and Windows 10, or alternatively (and probably better) look on the AVSForum/Calibration section at the Raspberry Pi pattern generator thread. To get a Pi to output HDR you need an additional HDMI Fury device (Linker is the cheapest). You will also need a sensor that is rated for 2000nits (assuming you have high end QLED).

HDR doesn't have blacker than black or whiter than white. I believe HDR uses a range like 64-940 or something like that which is why you need a HDR pattern generator. I think what the Pi/Fury does is the Pi outputs normal ranges but the Fury translates it to HDR equivalent and injects it into the output signal.

No TV supports full BT2020 so it's generally recommended to calibrate colour to 50% saturation. As I understand it most films are mastered in DCI-P3 colour space anyway (historically the industry standard) which is much smaller than BT2020 and high end TV's largely cover it. What happens when a 4K disc is mastered is that the DCI-P3 colours are translated to the same points in the much wider BT2020 gamut so that the colours remain accurate and very few discs currently contain colours outside of DCI-P3.
 

VHS Gamer

Active Member
I'm by no means an expert but as someone who has researched and dabbled in it I'll give this a go, anyone please correct me if I'm wrong.

Firstly, you will need a pattern generator that outputs HDR, you can achieve this using a modern graphics card and Windows 10, or alternatively (and probably better) look on the AVSForum/Calibration section at the Raspberry Pi pattern generator thread. To get a Pi to output HDR you need an additional HDMI Fury device (Linker is the cheapest). You will also need a sensor that is rated for 2000nits (assuming you have high end QLED).

HDR doesn't have blacker than black or whiter than white. I believe HDR uses a range like 64-940 or something like that which is why you need a HDR pattern generator. I think what the Pi/Fury does is the Pi outputs normal ranges but the Fury translates it to HDR equivalent and injects it into the output signal.

No TV supports full BT2020 so it's generally recommended to calibrate colour to 50% saturation. As I understand it most films are mastered in DCI-P3 colour space anyway (historically the industry standard) which is much smaller than BT2020 and high end TV's largely cover it. What happens when a 4K disc is mastered is that the DCI-P3 colours are translated to the same points in the much wider BT2020 gamut so that the colours remain accurate and very few discs currently contain colours outside of DCI-P3.
Wow thanks mmj. This is sounding though like the only way to really calibrate your TV for HDR is special equipment. What about the more basic ways of calibration like the Spears & Munsil UHD disc, right now it's the only one I know of offering test patterns for HDR. Using that would it be possible to set the correct black and white levels and colour?
 

mmj

Active Member
I don't know but I suspect as with SDR you'll only be able to get a very basic calibrations with those kinds of discs, your eyes are never going to be as accurate as a sensor. If you want a good white balance etc you're best off either buying the tools to calibrate it yourself which I admit can be a steep learning curve, or if you don't want to get your hands dirty pay a professional to calibrate it.
 

tonyoramos1

Standard Member
I don't know but I suspect as with SDR you'll only be able to get a very basic calibrations with those kinds of discs, your eyes are never going to be as accurate as a sensor. If you want a good white balance etc you're best off either buying the tools to calibrate it yourself which I admit can be a steep learning curve, or if you don't want to get your hands dirty pay a professional to calibrate it.
Once we have the hardware, where do we get the instructions to calibrate it? How do we know what we are looking for? And is this just for color? Someone told me that Dolby Vision is already calibrated. Thanks
 

mmj

Active Member
I don't know anything about calibrating Dolby Vision as my QLED only supports HDR so I've not looked into it, there may be a good factory calibration on it but I think the main point of calibration is that every TV is slightly different and manufacturers don't have the time to calibrate each one individually. To be honest my stock Q90T calibration seems good out of the box, it'd be hard to tell any difference pre and post calibration just going by naked eye.

First you calibrate the white balance and gamma (which are linked) and then the colour.

p.s. I forgot to mention before that a key difference in HDR calibration is to use a 10% window pattern rather than full screen (sdr).

I've used both HCFR and Calman, HCFR is free but has a really steep learning curve, Calman is lot more user-friendly but costs money.

Here are some guides I used:

HCFR

Calman
 
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