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

[AV2020]

https://eu.community.samsung.com/t5/tv/samsung-2020-t-series-tv-motion-judder-stutter-frame-rate/td-...

[_Frank83_]

I've tested the new firmware update with PS4 Pro connected on HDMI4 for a few hours and no local dimming issues anymore.

It took a while but at least it was fixed.

[Daveyboy123]

As per this, is anyone else having these issues? There doesn’t seem to be many posts on here about it but for me and some others some programs are barely watchable due to the extreme stuttering in low motion scenes etc. 

[jayh89]

This is an issue for me when using Virgin Media, watching BBC etc. it's not unbearable but it's annoying. Clearly an issue with refresh rate when watching cable/Sky TV.

[daparky]

Would this be an issue if games are running at 4k / 30fps?

[AZGreg]

Suriya: Why are you pretending to know about game needs? The console manufacturers themselves recommend you turn off contrast enhancer!

MJ1931: Again, it’s good you enjoy how your tv looks, but default setting are off. You even said you left sharpness at 10, which is a joke. Again, console manufacturers recommend turning sharpness off.

I swear, I could probably make a TV that costs half the price look better than whatever you two are looking at! 🤣

[ad1994]

Chill out a bit. Voice your opinion but this thread is just a big mudslinging match this week. 

[Suriya]

Come on guys don't be rude. Isf calibrations are only meant for BT.709 gamut which is primarily used in films and broadcasting industries. for gaming you have to keep DCI-P3 color space which looks oversaturated on non gaming content so you don't put some calibration disc under game-mode to calibrate it. My advice is always keep game-mode untouched. Just turn off GMP that's all

[MJ1931]

AZGreg Keyboard warrior acting hard, keeping use auto and warm2 and make your image orange, HDR needs contrast enhancer on full even a chimp knows that

[Suriya]

@AZGreg i don't pretend like i know everything just sharing my experience and my little knowledge.

Go to rtings.com and see recommended settings for gaming on 2017-2018 models once they recommend to turn off all picture enhancement options. After so many complaints about washed-out picture in game-mode on their comment section on both YouTube and website now they don't recommend to turn off anything under game-mode on 2019-2020 models. rtings itself learned by their mistakes and giving whatever is necessary.

Q95t is my 12th TV i have seen so many picture settings on different brands like sony/lg/tcl/samsung up to my experience what i learned is don't change game-mode default settings. So far q95t has the ultimate picture quality like other presets in game-mode, no other brand never did this before. That is the reason still I'm keeping this. When i saw this dimming bug i request return and bought lg 65cx then i realized q95t is still better on gaming so decided to keep it.