2020 QLED T models (Q80T, Q90T, Q800T, Q900T) HDR game mode brightness / local dimming bug

[Rauttis]

I bought a Q80T a couple of days ago and have noticed a really annoying issue when using the tv with the combination of HDR and game mode.

I'm fairly certain this is a software bug in the TV since I can reproduce this issue with 100% accuracy, and it happens on the dot at the same moment every time. It's basically on a timer.

Basically when the game is displaying a HDR signal and game mode is enabled, exactly after 6 minutes the brightness of the TV suddenly drops by around 20 (50 -> 30). The value of brightness setting doesn't actually change however. Messing with the brightness setting does not restore the brightness to it's original state, but changing the local dimming setting from standard to low and then back to standard does. Switching game mode off and then back on also fixes the issue, but then it happens again EXACTLY after 6 minutes (I've timed this with a stopwatch).

Has anyone else experienced this issue? Or can someone maybe test this on their TV to see if you can reproduce it?

Exact repro steps on how I can reproduce this 100% of the time on the PS4 Pro:

1. Set brightness to max (50)
2. Set local dimming to standard (bug happens on high as well)
3. Enable game mode
4. Turn off game motion plus
5. Turn off intelligent mode and all the brightness related settings in eco settings, as these can influence the brightness level of the tv.
6. Launch a game that runs in HDR
7. Start your stopwatch
8. Do whatever you want in the game or you can also go back to PS4 menus, find a bright scene where you can notice a brightness drop easily
9. When the stopwatch hits 6 minutes, you should see the TVs brightness suddenly drop by a large amount. By eye the brightness drop seems about equal to dropping the brightness from 50 -> 30 by hand.
10. Go to picture settings and set local dimming to low (brightness does not change)
11. Set local dimming back to standard (brightness suddenly jumps to the original level. Brightness can be restored by switching input away and back as well, or by disabling and re-enabling game mode)
12. And again after EXACTLY 6 minutes the bug again repeats and the brightness drops down again

Some other notes: The PS4 has a screensaver that basically dims the screen if it is idle for a while. This is not the cause of this, this happens even when the console is in active use and the brightness can be restored temporarily by changing the local dimming setting like described above. I have not managed to reproduce this issue with game mode off, so it seems to be related to game mode.

Software version: 1304

[MJ1931]

Lost post al,

You know better than Samsung on their game mode, everybody knows on game mode you have to use contrast enhancer to high, and local dimming to high,

one of you lot a few pages back had his HDR brightness at 30 and contrast enhancer off, haha just image and how dark it must be.

[MJ1931]

Long post al I meant

[MJ1931]

Do you touch anything on game mode SDR settings & HDR settings, I only touch dynamic black equaliser to 0, and it looks amazing

[Suriya]

All default looks stunning what all game creators meant to be. Even black equalizer 2 looks amazing it also helps pop up brighter areas and adding some blacks to all colors. Not only touches the darker area

[MJ1931]

Good man, I give settings a chance before changing them, other than that 6 minute dimming issue that is now fixed I found a Q80 & Q90 are amazing out of the box in game mode, dynamic equaliser I just found at 0 has better blacks in dark areas, but doesn`t crush.

One of these guys was using:

Game mode HDR brightness 30, contrast enhancer off, auto colour, and warm 2 just messing with it for the sake of it basically.

[CypherXCII]

@Suriya im really curious what kind of settings you use for hdr gaming. Would you able to share it with us?

[AV2020]

So many noobs in here. People on Avforums would be laughing at you and all the game developers and isf foundation and calibrators. So funny. 

[AV2020]

Yes HDR will set your brightness and contrast at 50. That is how it should be, not sure who changed it back to 30. That would be wrong and dark.

Contrast enhancer to high😂

Way to blow out the highlights between dark and light.  Looks brighter, but affects the HDR range between dark and light. Best to have it on low or off. You would only need contrast enhancer on if you had a poorer lower nit TV. T Series produce good HDR images. So it is not needed and detrimental to the image. 

[MJ1931]

I would love to know your HDR game mode settings, I feel like a laugh, bet it involves warm 2 haha

[MJ1931]

My guess is HDR Game mode

Contrast enhancer off

Local dimming low

Auto colour

Warm 2

Fell like throwing up