Q85R Local dimming bug in HDR streaming - Sudden brightness loss

[john1979]

Steps to reproduce

1. Open any native streaming app that supports HDR (eg. Netflix, Prime, AppleTV+)
2. Start an HDR movie
   • Movie Mode, Brightness 50, Local Dimming High, Contrast Enhancer (None or Low)
   • Intelligent Mode off, Eco off
3. After a few minutes of great looking HDR, brightness suddenly drops and picture looks worse than SDR. The issue is very noticeable. Even guests notice the issue on their first viewing on the TV. Now on the the "fix".
4. Open TV Settings > Picture > Expert Settings > Local Dimming
   • Switch from High to Low, then back to High
5. Picture is back to normal for a few minutes, then brightness suddenly drops again.
   • The "Brightness" value is still 50 of course, not to be confused.

It's been like that since I bought this TV more than a year ago and hasn't been fixed yet.

Basically makes the TV super annoying and a really bad buy for watching HDR content.

Update: I just discovered it's not just my model.  

If anyone with the same issue has tried streaming with an external streaming box please let us know.

[Darksephirott]

I have a Q80R and I have the same problem, according to the content sometimes it happens and sometimes it does not, it is very annoying, I hope it will be fixed some day.

[Peto Pedro]

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[Stu123]

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[Peto Pedro]

There is no any bluray player hdmi  only hdmi 1and 2 then hdmi 3 earc and hdmi 4 with game 

I don't even have in game bcos I wouldn't have 4k@120 on min 1660 super 

I have brightness on 25 or 30 as it drains electricity very much on 50 

contrast is on 40 the higher contrast it will wash the shadows out  I prefer cool instead of warm as the whites are real white not yellow.. But tv  millisecond is terrible yeah I can see how it drags... 

[Stu123]

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[john1979]

Obviously nothing is being done to address this issue, 2 years after buying..

I just wanted to add that the same behavior also occurs when hooking up a PC via HDMI and using HDR mode in windows.  The same sudden brightness drop occurs every few minutes.

It's frankly unbelievable how many models have this bug and there is not a single mention from the big TV review sites.

[Peto Pedro]

In reality the hdr wans't designed for your desktop work  on pc... it is only used for movies..

[c4tech]

This is a result of the contrast enhancer feature being enabled. 

I’ve thoroughly tested with Q80A

[Davey_D]

This definitely isn't the case with my q90r. No disabling of options helps. Disabling contrast enhancement simply decreases the severity as the screen goes from relatively dull to dark, rather than bright to dark