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Discussion Starter · #1 ·
I apologize if this has been covered before, but I'm wondering if anyone has an explanation for black crush with the Netflix app playing Dolby Vision on both the new ATV 4K as well as the previous 4K box?

I have an LG C9 OLED and with both the new generation and previous generation devices there is serious black crush to the point that some content is almost unwatchable. If I switch to the television's built in app the content appears fine. The same video settings are being used in both cases.

I had hoped this was an artifact of the older hardware but unfortunately this does not appear to be the case. I have not observed the black crush to this extent with other ATV apps playing DV content.

Is this a known issue or is it worth trying to get Netflix or Apple to do something about it?

I can provide photos of what I'm seeing if that would be helpful.
 

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That is most strange. I have a C8 and recently swapped out the ATV4k Gen1 with the new ATV4k Gen2. I haven't seen black crush to the extent that you mention with either one. That being said, I don't watch the C8 in a totally dark room. I use a bias light on low at night.
 

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Discussion Starter · #3 ·
That is most strange. I have a C8 and recently swapped out the ATV4k Gen1 with the new ATV4k Gen2. I haven't seen black crush to the extent that you mention with either one. That being said, I don't watch the C8 in a totally dark room. I use a bias light on low at night.
I'll take some photos later tonight, the difference between content on ATV vs the build in TV app is dramatic.
 

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Could you provide screengrabs of your ATV video settings as well as your LG video settings?

Really bad black crush is usually a sign of a signal mismatch, with the player sending a FULL RANGE signal but the TV expecting a VIDEO RANGE signal.
 

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Discussion Starter · #5 ·
Could you provide screengrabs of your ATV video settings as well as your LG video settings?

Really bad black crush is usually a sign of a signal mismatch, with the player sending a FULL RANGE signal but the TV expecting a VIDEO RANGE signal.
Thanks, yes I am familiar with this kind of mismatch causing a problem from many years of setting up HTPCs with XBMC, Kodi and Plex where these kind of problems were ever present.

Of course for the built in streaming apps on the C9 the only settings that can be controlled are just the video settings.

In the case of the ATV 4K it is set up with source matching, DV & YCbCr and 4:4:4 and is using certified HDMI 2.1 cables. I can provide more settings later, or screen caps of specific settings you are interested in.

Unfortunately because of the automatic processing on my iPhone the quick photos I took don't really do the problem justice, it's more noticeable in person. The first image is from the C9 built in Netflix app and the 2nd image is from the 4K ATV Netflix app. Both are displaying in DV and have the same panel/video/colorspace settings. I can provide more info if it would help.

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Thanks, yes I am familiar with this kind of mismatch causing a problem from many years of setting up HTPCs with XBMC, Kodi and Plex where these kind of problems were ever present.

Of course for the built in streaming apps on the C9 the only settings that can be controlled are just the video settings.

In the case of the ATV 4K it is set up with source matching, DV & YCbCr and 4:4:4 and is using certified HDMI 2.1 cables. I can provide more settings later, or screen caps of specific settings you are interested in.

Unfortunately because of the automatic processing on my iPhone the quick photos I took don't really do the problem justice, it's more noticeable in person. The first image is from the C9 built in Netflix app and the 2nd image is from the 4K ATV Netflix app. Both are displaying in DV and have the same panel/video/colorspace settings. I can provide more info if it would help.

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Would need to see the exact settings on the ATV / LG to say. Those pictures look almost identical on my computer though, so it is unlikely to be a Full Range/Video Range mismatch.
 

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Discussion Starter · #7 ·
In re-reviewing my settings I see that for HDMI input 3 the peak brightness is set to off. At some point this was either changed due to a firmware update or I inadvertently turned it off.

While the picture is more accurate with this turned off it greatly reduces the panel light output to perhaps 300 nits.

When I turned it to high, which is where it is set with the settings for built in apps, the pictures look more similar so I'm going to chalk this up to this setting causing the problem unless I am able to make a more specific determination.

Portrait have updated their Calman software and I think my license is still eligible for an upgrade, so I might also re-calibrate the TV with the latest software available which takes a few more things into account.

Thanks.
 
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