Apple TV 4K Issue - Grainy HDR Effect?

[shiggypoo]

Hello! New to the forums here as I’m in the process of setting up a new 4K Apple TV on my UN55MU8000 and am running into some grain issues when HDR is enabled.

As per the attached pictures, whenever I pause a movie with black bars there is a significant amount of noise/grain at the bottom of the picture, from the progress bar overlay effect. This only happens when HDR is enabled and I've tried changing chroma from 4:2:2 to 4:2:0 with no luck. When in 4K non-HDR the progress bar appears as normal with the shadow effect being processed correctly.

A few notes:

• I am directly connected from ATV 4K into HDMI 1 on the Samsung One Connect using a high speed Belden HDMI cable (it's not HDMI 2.0 certified but the same cable experiences no issue with my PS4 Pro; it's a heavy duty cable!)
• UHD HDR is enabled on the Samsung for this input
• Apple TV is set to display the original format (although I’ve tried the default where it processes the image, and experience the same issue)
• No issues playing HDR content from PS4 Pro, Smart Hub apps, etc.

I should also add that depending on the scene, the grain at the bottom isn't always as noticeable. Usually dark scenes show it more but in many well-lit scenes it will also do it. The odd time when I check, depending on the scene, it may be gone almost altogether.

Is this perhaps a normal expectation of HDR on the ATV, or if not would anyone have any suggestions on how it can be eliminated? Thanks in advance!

 

[tliede20]

Shiggypoo, I have this setup:

- Samsung Television 65" Class MU8000 4K UHD TV

- Apple TV 4K - Apple

- Denon AVRX1400H Receiver

- Cinnamon HDMI Cables (1m)

- Belkin 4K HDMI Cables

and I'm having trouble even getting decent color, everything looks muted, does your Home Screen look muted "saturated"?

 

[shiggypoo]

Shiggypoo, I have this setup:

- Samsung Television 65" Class MU8000 4K UHD TV

- Apple TV 4K - Apple

- Denon AVRX1400H Receiver

- Cinnamon HDMI Cables (1m)

- Belkin 4K HDMI Cables

and I'm having trouble even getting decent color, everything looks muted, does your Home Screen look muted "saturated"?

The home screen in HDR mode does look too bright and a bit washed out. What I did do to fix that is override 4K HDR in settings and choose 4K SDR, as well as also choose for the Apple TV to pass on the original film content (part of the December patch from what I’ve read)

That way when you play a movie it switches to HDR mode, while the home screen and other apps look much better at the same time.

Glad to see someone else with the same series Samsung. Are you by chance experiencing the grainy effect during pausing/scrubbing HDR content? It only occurs over top of the bottom black bar, or if 16:9 HDR content, if there are dark areas where the shadow effect is overlaid.

Trying to determine if my ATV or Samsung TV are faulty, or if it’s just a glitch on the ATV software

 

[msama]

FWIW, I had random issues with HDR with my 4k atv, I was using a solid HDMI cable I've never had any issues with other 4k devices, I bought a 4k branded HDMI cable to test and have had zero issues since. I know it shouldn't matter, but it may be worth testing.

 

[err404]

I believe that your TV is an LED LCD (last years 8000 series was QLED). This tech will struggle with HDR since the backlight will be a max brightness will have more bleed through.
When you bring up the menu, the grid array on the backlight will brighten the bottom edge in order the illuminate the bright white progress bar.
You can try reducing the backlight some, but this will hinder the HDR effect, you can also try playing with the local dimming strength.
Keep in mind that your picture setting for HDR and SDR are independent from each other and need to be calibrated separately. HDR can make the image seam dark. If you raised the brightness (aka black level) to compensate, you may have brightened the black level to a dark gray. Try reducing the brightness and instead increase the gama to compensate for the darker picture.
I hope this helps. This may just be something that you will have to live with. Hopefully it is not too distracting when the film is actually playing.

 

[shiggypoo]

Thanks for the response! The TV and Apple TV were both new so I didn't realize that HDR had its own independent settings to be changed. I originally tweaked Natural mode to look great for SDR content but didn't realize that the Natural HDR mode had dynamic contrast effects turned on, etc. Set HDR pictures to movie mode, dropped temperature back to Warm1 for preference and now there are zero issues with the shadow effect. HDR content looks even better as well.

 

[idntknw]

Sorry for the bump but didn't want to start a new thread after reading err404s reply. I have the 65MU8000 and when I have the format at 4K 60Hz everything is very dim. Menus, movies everything. I change the format to 4K SDR 60Hz match content range and frame rate the menus look normal but the content is still very dim. Turn off match content and movies are back to normal.

Guess the main issue is that HDR content is very dim.

Is this a issue with the tv?