Calibrating HDR

[Safari Ken]

Hello! I recently got a TCL 65r617 TV, and it's been spectacular. Way better than I'd expected, even. One of the first things I did, as with any TV, was calibrate the image using a blu-ray with test patterns (I forget the name of the disc offhand, but one of the main ones I guess). Like many TVs, the TCL has separate settings for each input and for HDR and SDR, Dolby Vision, etc.

Initially, I simply ported over the calibrated SDR settings to the HDR settings, and things look just swell. But then I did that for a Dolby Vision input, and it looked like garbage. I realized that Dolby Vision maybe shouldn't be calibrated, since it's already kinda calibrated in the first place. Maybe I'm wrong about that, but putting Dolby Vision on default made things look great again.

But that made me start thinking about the HDR calibration. I decided that I'd like to calibrate the HDR specifically, but I can't figure out a way to trick my TV into going into an HDR mode, while still seeing the test patterns.

So this was a long-winded way to ask, do any of you have any tips for calibrating HDR? Unlike Dolby Vision, I feel like it needs to be calibrated, but as good as it looks now, I'm the kind of guy who wants to make sure. But I'm also the kind of guy who doesn't have a lot of cash to spend on a hardware densitometer, just for this one thing.

Thanks!

[StingingVelvet]

There are HDR test patterns on Sony discs. Input "SONY" on the numberpad on the main menu. They're just your basic stuff though.

[Safari Ken]

Hey thanks, I didn't know that! I don't need anything too crazy; I feel like the color settings are pretty dead-on. I mainly want to confirm to myself that the brightness and contrast are correct.

[ROSS.T.G.]

I wouldn’t port you SDR settings to HDR. Blu-ray calibration discs are great for setting contrast and black level, sharpness etc but the same settings won’t work for HDR. Without a meter and software I wouldn’t change any settings in HDR mode. Changing backlight and contrast will probably mess up your tone mapping. Just turn off all the extra processing noise reduction etc. If you’re still unhappy then it’s time to hire a pro and perform a true calibration.

[brian9229]

I'm pretty sure 4k uhd test color patterns require a colorimeter.

[IntelliVolume]

This is something I have thought about for awhile, too...I feel like HDR should be "calibrated" separate from SDR, but then I think the factory defaults the TV manufacturers select for HDR content are the settings you should be using...for instance, when my Samsung goes into HDR mode, it automatically maxes out the backlighting and contrast and turns the local dimming (on my edge-lit set) to "high," while also selecting the correct gamma curve for HDR. I feel like these shouldn't be "messed with" (other than, in my case, turning local dimming to "low" because "high" creates horrible flashlighting and gray-ish blacks to say nothing of the aggressive dimming algorithm being set off; to be honest, though, I tried watching the Equalizer 2 4K Blu-ray with local dimming on "low," which is what I use for SDR content, and it seemed like the brightness range was severely held back...could have just been placebo though)…

Should parameters like contrast, backlighting and perhaps local dimming be left to the display's chosen defaults for HDR content playback?

[ROSS.T.G.]

Originally Posted by IntelliVolume

This is something I have thought about for awhile, too...I feel like HDR should be "calibrated" separate from SDR, but then I think the factory defaults the TV manufacturers select for HDR content are the settings you should be using...for instance, when my Samsung goes into HDR mode, it automatically maxes out the backlighting and contrast and turns the local dimming (on my edge-lit set) to "high," while also selecting the correct gamma curve for HDR. I feel like these shouldn't be "messed with" (other than, in my case, turning local dimming to "low" because "high" creates horrible flashlighting and gray-ish blacks to say nothing of the aggressive dimming algorithm being set off; to be honest, though, I tried watching the Equalizer 2 4K Blu-ray with local dimming on "low," which is what I use for SDR content, and it seemed like the brightness range was severely held back...could have just been placebo though)…

Should parameters like contrast, backlighting and perhaps local dimming be left to the display's chosen defaults for HDR content playback?

Yeah I wouldn’t fuss with your HDR settings. Your particular sets backlight should be set to max and local dimming set to high.

[avs commenter]

Apple TV and THX tune up app. You can calibrate while in DV

[IntelliVolume]

Originally Posted by ROSS.T.G.

Yeah I wouldn’t fuss with your HDR settings. Your particular sets backlight should be set to max and local dimming set to high.

Thank you, Ross. I'm gonna leave backlighting to max, but should contrast also be set to max?

With regard to local dimming -- because I'm dealing with an edge-lit set (I'm gonna be looking into bias lighting kits soon), the "high" local dimming tends to really show flashlighting in the blacks and letterbox areas in films that look way too elevated (they're almost gray, which is typical with this tech). Do you think I can get away with putting local dimming to LOW when watching HDR content to deal with this?

[ROSS.T.G.]

Originally Posted by IntelliVolume

Thank you, Ross. I'm gonna leave backlighting to max, but should contrast also be set to max?

With regard to local dimming -- because I'm dealing with an edge-lit set (I'm gonna be looking into bias lighting kits soon), the "high" local dimming tends to really show flashlighting in the blacks and letterbox areas in films that look way too elevated (they're almost gray, which is typical with this tech). Do you think I can get away with putting local dimming to LOW when watching HDR content to deal with this?

Yep, I would leave it as is. I would just reset your HDR mode and make sure HDMI UHD Color is ON.

I would leave on high. Unfortunately that’s a downside that can’t be avoided, blacks will appear more grey. I had that issue with my first LED 4K. Bias light should help.

[StingingVelvet]

Originally Posted by brian9229

I'm pretty sure 4k uhd test color patterns require a colorimeter.

The Sony discs have basic contrast patters and whatnot, but in HDR. That's what I think he wants. I wouldn't adjust anything other than gamma, brightness and contrast without professional calibration equipment.

[Safari Ken]

I think over the years, I just got it in my head that calibration is the very first thing that should happen on a new TV, because default settings on TVs have always been crap. (Also, I worked in a film lab for years, so I feel like I might be oversensitive to bad picture quality. )

But last night, I was watching the Big Lebowski, and the picture was fine but not blowing me away, so I decided to try your advice, and switched the HDR back to default (except for necessary stuff like correcting the "Sharpness", turning off motion smoothing, etc.) And boom, the picture started blowing me away. So much so that even though I was tired, I watched all of Thor Ragnarok, mouth hanging open.

So I'm glad I posted here, or I wouldn't have thought to do that, just out of sheer habit. Now I feel like I haven't really watched any of my 4k blu-rays, so I've got a busy week ahead. Thanks everyone!

[IntelliVolume]

Originally Posted by ROSS.T.G.

Yep, I would leave it as is. I would just reset your HDR mode and make sure HDMI UHD Color is ON.

I would leave on high. Unfortunately that’s a downside that can’t be avoided, blacks will appear more grey. I had that issue with my first LED 4K. Bias light should help.

Thank you. Yes, HDMI UHD Color is definitely on.

What would be the downside of running local dimming on LOW for HDR? From what I have read, these local dimming algorithms on the Samsung edge-lit sets don't actually do much of anything, so what would be the benefit of leaving it at high?

[HDMan72]

Originally Posted by IntelliVolume

Thank you. Yes, HDMI UHD Color is definitely on.

What would be the downside of running local dimming on LOW for HDR? From what I have read, these local dimming algorithms on the Samsung edge-lit sets don't actually do much of anything, so what would be the benefit of leaving it at high?

When I had a Samsung edge-lit tv I used local dimming on high and noticed it helped add some highlights to HDR. It was always recommended to be set to high from fellow Samsung owners over at AVS Forum.

[IntelliVolume]

Originally Posted by HDMan72

When I had a Samsung edge-lit tv I used local dimming on high and noticed it helped add some highlights to HDR. It was always recommended to be set to high from fellow Samsung owners over at AVS Forum.

Thanks HD Man. I can leave it on high with HDR playback, but the elevated black levels and flashlighting when doing so are horrible...

Leaving it on low is okay for SDR?

[IntelliVolume]

Can anyone confirm if using local dimming on LOW (on a Samsung edge-lit set) is okay for SDR content?

[StingingVelvet]

Originally Posted by Safari Ken

I think over the years, I just got it in my head that calibration is the very first thing that should happen on a new TV, because default settings on TVs have always been crap. (Also, I worked in a film lab for years, so I feel like I might be oversensitive to bad picture quality. )

Movie modes are pretty accurate out of the box for most brands now-a-days. Not the same as a pro-calibration but pretty accurate. All I did on my Samsung was raise gamma one point ("lower" by their metric, but it raises it), everything else is stock movie mode settings.

[slimdude]

A person shouldn't have to do anything to the HDR setting on their TV because it's already preset from the manufacturer. On the LG, the HDR setting has three levels of brightness: low, medium and high. I choose the one that looks the best, and that's it.

[oddbox83]

Originally Posted by slimdude

A person shouldn't have to do anything to the HDR setting on their TV because it's already preset from the manufacturer. On the LG, the HDR setting has three levels of brightness: low, medium and high. I choose the one that looks the best, and that's it.

That's a lot of trust in the manufacturer to have got it right, many certainly don't!

Thankfully, modern LGs do have good out of the box settings, once you dial down all the "enhancements" anyway.

Originally Posted by IntelliVolume

Can anyone confirm if using local dimming on LOW (on a Samsung edge-lit set) is okay for SDR content?

Depends on the individual TV, since edge-lit displays are so variable even within the same model. If there is pretty bad clouding and bleeding, you might have to have it on medium at a minimum. It's a balancing act.

[Deciazulado]

The Sony UHD Menu: 7669 Enter grey patterns can be used with a light meter* to check the PQ tone curve. If you change the LCD backligtht/OLED light to brighter/darker you can still use them but then recalculate the aim values.

(So if you wanted to set HDR 100 nits as 70 or 140 etc. for some reason, instead of values reading:

1000 (nits)
500
100
50
10
5
1
0.1 etc

they should read**

700
350
70
35
7
3.5
0.7
0.07 etc

or

1400
700
140
70
14
7
1.4
0.14 etc

accordingly)

You can use them to check if overall grey scale / color temperature is close to neutral but Andreas and I have checked and the grey pattern doesn't measure perfectly neutral for PQ expansion, btw.


*If you don't have a light meter, you can use a good camera's meter set up to ISO 100 f/2.8 (or any equivalent ISO/aperture combination to that) to get ~ nits, as in 1/shutter speed = 1/nits, (k factor 12.5, depends on the meter k factor. With factor k14 should actually be 1/shutter speed x 1.12 = nits)

**(According to theory if you make the image darker or brighter from standard, or change surround*** room walls light (for example from totally black walls in no room light to bright walls in room light) you should also adjust image gamma (image contrast) a little, probably a range 1.1x for darker image/surround to 0.9x brighter image/surround, so you could adjust the values accordingly.

***(The visual angle of view the screen covers in front of you can affect also the screen/surround gamma ratio factor )