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

[jmb0]

Before this 1402 update, VRR did get incredibly dark. Now VRR has no bearing on how dark it is. It's that level of dark all the time now with HDR on. Before the update, HDR was fine until it timely dimmed.

I did test in SDR. It looks okay, I guess, but I've been spoiled by HDR. The screen brightness perfectly fine in SDR.

HGIG is doing nothing for me.

The only gamma option I have is ST.2084. To get the brightness up to SDR level, I have to have ST.2084 Gamma all the way up to 3, and Contrast Enhancer on High.

Yes, 1402 is the update that came out today.

[Keitoki]

let's report him, he tried to delete his previous messages

[HQboy]

stop it. Focuses on the issue of firmware. You will solve your intrigues in a private message with him if you want.

[Smooky]

To be fair i wouldn’t mind darker HDR as long as local dimming works fine

[QuantumP]

[QuantumP]

Asking for money for the link “donate to technician” for the link😂 Deleted the same post on these forums too. He is something else.

[Keitoki]

yep stop it, let him scam everywhere 😂

[HQboy]

So that was my doubt, if the local dimming is working perfectly now. And how is the Blooming question.

[HQboy]

Have you reported? Then it was over. You don't have to post all the time.

[Chast]

you will never get full local dimming in game mode, don't think about it too much.

it is impossible without raising the input lag