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]

Hey Guys

Just looking at previous posts about picture settings for TV (HD & 4K) NOT HDR, seem to be over complicating things, try these, dead easy just 5 adjustments from default

Filmmaker Mode (make sure its reset to default first)

ECO settings off

Picture Size 16:9 fit to screen on

Contrast Enhancer High

Colour Tone Standard

Colour Space Native

HDR will be automatically calibrated it you use Filmmaker mode, try that youtube LG video with food and drink 4KHDR

[Danmay]

Hi Guys,

Thought I'd weigh in here, as I work for an electrical retailer, and I finally went for a q90t after seeing it on display for months.

Safe to say I'm having all the issues mentioned here, even after performing the update via USB today.

The most surprising issue is the faint scrolling lines that are visible with GMP off and/or VRR on. These are easily visible on any solid colour. This is very odd and not something I've seen on a modern screen. This issue is only resolved by turning GMP on, and then reducing every value to 0 to get the lowest input lag time.

Yes, VRR/Freesync is dark, and there doesn't seem to be a way around it. My concern is, myself and others have got this screen purely on the basis of it supporting 4k 120 with VRR. However, VRR doesn't seem to work correctly.

Another thing I've noticed (coming from a sony 9005) is that the pixel response time isn't amazing. There is definitely more 'smearing' due to higher response times of the pixels, especially compared to my old sony.

My concern is that these issues won't be fixed, as more casual users won't notice them... (I'm aware pixel response times are down to the panel and can't be updated).

[jayh89]

Interesting. I can’t test VRR cos I don’t have an Xbox. It might be best to set up a new thread on this forum for exposure though!

[Suriya]

The problem is everybody is mixing their model numbers here. Q95t has no issues 

[QuantumP]

Over complicating things? Well if you can’t copy someone’s professionally calibrated settings, I dread to think what else you struggle with in life. Your settings are wrong for a start and inaccurate and bad. 

[AV2020]

Vrr working perfectly here on Q95T. No darkness whatsoever. Not sure what the issue is with other users. 

[BogaMoge]

Hi, I have a 55Q90T too and have the same problem as yours.

I am curious though, what color is the "smearing" you attribute to bad pixel response time? For me, it's a purple behind dark shapes on light(er) background, during dark scenes. Especially noticeable when camera panning or rapid camera movement while playing games.

I have talked with a Samsung tech on the WhatsApp customer line and here is what he said : it is caused by a HDMI connection problem.
Doubtful, I tested the theory by watching a gameplay video I uploaded to YT, once on my PC connected by HDMI, and another directly from the TV's app.
Results :

• ghosting (or "smearing", don't know how to call it exactly) on PC
• no ghosting on the app

Which would tend to prove his theory true...
The tech then told me another update was in development to solve HDMI problems (ghosting and flickering being the main ones apparently) on Qled 2020 models, but wouldn't (of course) give me any kind of date.

Now please take all this with a lot of salt, this is just one person on the WhatsApp customer service of Samsung, I have no way of knowing if he was talking out of his ass or being genuine. I can only confirm the test (HDMI/not HDMI) worked even when I tried it again later.

But since you seem to have some experience, and to have similar issues as mine, how would you weigh in on that HDMI theory?

[CypherXCII]

As i said: i've a q95t with vrr on my Xbox one x enabled with no dark screen. I've set my brightness on 30, local dimming on high and contrast enhancer on low. that's the way i like it. There is no difference with vrr on or off: 

 

 

[jayh89]

Wonder if anyone here has a Q85t and able to tell me if any difference with VRR on and off??

[MJ1931]

Warm colour tone is just red, auto colour space washes out an image

Movie mode was the best of a bad bunch before filmmaker mode, movie mode will be dead in 6 months, filmmaker mode is the the the most true base image to work from, its stripped back (blank canvas almost)