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Hi Dominic.. For my set up.. rs640 with javs curves, oppo 203, vertex2 and now ordering appletv will I be having this red tint problem some are talking about on the thread.. If is a bug that hasn't been figured out I rather just sit and wait till you guys figure it out rather than experimenting right now.. I am confused because some see it and some don't?
Im not sure if anyone has tracked down the cause of the red shift.
 

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Do you get the red tint as well.. If not then i could be in luck as i have the same exact set up as you..
The post you quoted shows what I’m getting.
 

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The values will make no difference in the output LLDV.

They may make a difference in how your display performs HDR10 tone mapping. That would be display specific and you would need to know what values would be good or bad for its tone mapping.

With a fixed HDR curve like many projectors have, the values should make no difference. It would be the curve itself that would make a difference.
Thanks claw!
 

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Here's another set of comparison pictures - EDID5, EDID5 with Custom Profile, HDR10.
Source is Netflix playing Bletchley Circle S1E3, HD converted to HDR.
Note that this particular scene is reddish even with HDR10.
Thanks for the comparison. Unfortunately it doesn’t seem like US Netflix subscribers have this show available.

To me, it seems the last one, HDR10, shows the least amount of red tint. Is this Netflix through the ATV?
 

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Thanks for the comparison. Unfortunately it doesn’t seem like US Netflix subscribers have this show available.

To me, it seems the last one, HDR10, shows the least amount of red tint. Is this Netflix through the ATV?
Yes, Netflix was through ATV4K. The issue is indeed red tint when using the LLDV EDID, especially for SDR (with Range Match off)

When I have time I may do a similar comparison on the Fire TV Cube.
 

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Yes, Netflix was through ATV4K. The issue is indeed red tint when using the LLDV EDID, especially for SDR (with Range Match off)



When I have time I may do a similar comparison on the Fire TV Cube.


Keep in mind the true source of the material you are viewing. That movie is HDR or DV? I think it’s HDR which is what I am seeing. Anything on ATV4K that is NOT DV is showing red tint. That is what I said earlier. However if the content is DV (Harry Potter series) there is no red push from my observation.

I think we have too many variables here and not enough people (including me) holding one constant during tests. For ATV4k we get material in SDR, HDR, and DV. We are now using a vertex (most likely version 2) which now has more variables like setting EDID5 or clicking automix and force LLDV.

Then we add on people’s custom colour profiles, custom curves. Then we have different projectors, etc, etc.

For me, I have ATV4K, vertex2, denon AVR with DV pass through and finally JVC x770. I am using a custom curve I have always been using for HDR content but thinking of just using the built in HDR setting as the x770/790/970/990 projectors have “reasonable” built in hdr profile.

Will report back when I get time.


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I think we have too many variables here and not enough people (including me) holding one constant during tests. For ATV4k we get material in SDR, HDR, and DV. We are now using a vertex (most likely version 2) which now has more variables like setting EDID5 or clicking automix and force LLDV.

Then we add on people’s custom colour profiles, custom curves. Then we have different projectors, etc, etc.
That’s why I only post comparison shots, changing only one variable at a time. The pictures show the differences resulting from the change in variable, and are not meant to show the “absolute” red push, brightness etc.
 

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That’s why I only post comparison shots, changing only one variable at a time. The pictures show the differences resulting from the change in variable, and are not meant to show the “absolute” red push, brightness etc.


Yup I agree and effective. Not saying it isn’t but should we be focusing only on DV content first to see if this “hack” is giving good results as intended? Then move to potential HDR and SDR conversions? I dunno.


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Yup I agree and effective. Not saying it isn’t but should we be focusing only on DV content first to see if this “hack” is giving good results as intended? Then move to potential HDR and SDR conversions? I dunno.
I agree, if the objective is to help decide whether there is any ad advantage in going with the DV hack. My first set of pictures were intended to do that.

This particular set was meant (primarily for atabea) to show the effectiveness (or lack thereof) of the custom filter to reduce the red tint.
 

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That’s why I only post comparison shots, changing only one variable at a time. The pictures show the differences resulting from the change in variable, and are not meant to show the “absolute” red push, brightness etc.
Your comparisons are extremely helpful - it's quite difficult to quantify the differences that single variables make to the image with my projector due to the 15s plus resync time you get every time you change mode.

Personally I hesitate to call this a simple red push - I think there's more going on here, not only due to the colour space but also the rolled off PQ curve - don't forget a standard PQ is not tone mapped - it doesn't roll off - this is only required as the display dictates and tone mapping incurs it's own hue changes and since we can't decode the Dolby VSVDB we can't know that tone map, but it's certainly not geared for our displays!

I've been reading the original thesis on IPT - the colour space on which Profile 5 is based and the colour encoding, ICtCp (confusingly also known as ITP), that follows and it seems to me that trying to squirt a profile 5 signal into Rec.2020 PQ is, to quote a great man out of context, like asking the Suez Crisis to pop out for a bun. A bit of a mismatch. There's a lot more to it than just matching primaries.

So I'm sticking by my original feeling - it's a fascinating experiment, but when it comes to actually taking time to sitting down in the cinema with a chilled glass of chardonnay and a packet of crisps to watch a movie that someone has sweated blood over grading, I'll be watching using a well honed gamma curve and the correct colour space.

Until I finally get around to lashing out for an N7 that is ;)
 
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Personally I hesitate to call this a simple red push - I think there's more going on here, not only due to the colour space but also the rolled off PQ curve - don't forget a standard PQ is not tone mapped - it doesn't roll off - this is only required as the display dictates and tone mapping incurs it's own hue changes and since we can't decode the Dolby VSVDB we can't know that tone map, but it's certainly not geared for our displays!
I tend to think that tone mapping affects primarily the bright colours (explosions, sunlit scenes in deserts, etc). Tone mapping should not affect levels lower than diffused white, other than the multiplier which should not cause noticeable hue and saturation changes. Skin tones are typically at lower luminance levels than diffused white.

So I'm sticking by my original feeling - it's a fascinating experiment, but when it comes to actually taking time to sitting down in the cinema with a chilled glass of chardonnay and a packet of crisps to watch a movie that someone has sweated blood over grading, I'll be watching using a well honed gamma curve and the correct colour space.
Or I can live in a fool's paradise, turning on DV assuming/imagining it will give me a better picture.:)

(ATV4K displays a prompt saying “Let’s get you the best picture” when asking you to turn on DV).
 

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I tend to think that tone mapping affects primarily the bright colours (explosions, sunlit scenes in deserts, etc). Tone mapping should not affect levels lower than diffused white, other than the multiplier which should not cause noticeable hue and saturation changes.
Absolutely right when we're not mixing and matching standards - but if we had more information about what the Dolby block is telling the player we'd be in a much better position. I'd love to see the spec for that!

Or I can live in a fool's paradise, turning on DV assuming it will give me a better picture.:)
Very good point well made :D
 

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Discussion Starter #474 (Edited)
I tend to think that tone mapping affects primarily the bright colours (explosions, sunlit scenes in deserts, etc). Tone mapping should not affect levels lower than diffused white, other than the multiplier which should not cause noticeable hue and saturation changes. Skin tones are typically at lower luminance levels than diffused white.



Or I can live in a fool's paradise, turning on DV assuming/imaging it will give me a better picture.:)
Does that mean the Honeymoon is over? :grin:

I'm planning to continue to use LLDV for DV and HDR10 source content on the ATV4K and with disc content on the x800m2.

I will keep the ub820 tuned and ready to run SDR2020 for any problem DV/HDR10 disc content.

I will use the ub820 for HD SDR disc content, and i will put the ATV4K into Match Range to output any HD SDR content as 4k SDR.

I see a difference using LLDV with DV and HDR10. In a growing majority of instances, I prefer the LLDV processing.

While I am happy using Chad's curves, I am curious about testing a more aggressive "1000 nits" range curve. Maybe the Javs 80?

While DH has noted better results, I have yet to see any benefit to putting SDR thru the LLDV process, given the offset calibration required of a custom curve or onboard HDR st2084 controls.

I have no expectation hdfury will offer an update to expand access to the LLDV processing, but I'll be ready to give it a try if they do. :wink:

Thanks to all who have participated in the adventure. :) I have no regrets, for the cost to play was small.

(ATV4K displays a prompt saying “Let’s get you the best picture” when asking you to turn on DV).
Maybe if Siri said it in a soft, sultry voice, it'd be even harder to resist? :devil:
 

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So, after testing DV encoded disc playback over the past few days, and even when using the AUTOMIX as opposed to CUSTOM, I cannot achieve a satisfactory picture that is not plagued with a red tint. Out of the 14 DV discs I have tried, only two were largely unaffected by the red push. In view of those results, I returned my Sony X800M2 (which I bought for the sole purpose of trying this hack) today. I am now ready to pick up the ATV to continue testing with that platform. However, before I do that, I am hoping that @Dominic Chan and @tswire could post some comparison pictures of:

DV encoded programs (not HD or SDR) using LLDV output from the ATV, followed by HDR 10 using regular Custom Curves. Hopefully, ATV is processing LLDV in a way that eliminates the red tint.
 

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DV encoded programs (not HD or SDR) using LLDV output from the ATV, followed by HDR 10 using regular Custom Curves. Hopefully, ATV is processing LLDV in a way that eliminates the red tint.
Netflix on ATV4K sends all HDR as Dolby Vision. There isn’t anything that’s HDR10.

BTW, even with LLDV you still need a pot pick a curve, custom or not.
 

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ATV4K sends all HDR as Dolby Vision. There isn’t anything that’s HDR10.

BTW, even with LLDV you still need a pot pick a curve, custom or not.
Wasn't aware that ATV was 100% DV. If you get the chance, can you please post a couple more pics showing skin tones. @tswire, can you also post a couple of samples so we can get an idea what you are seeing? Yeh, while running LLDV with the Sony and Panasonic players, I used your curves, Javs' curves and even some I created myself.:D
 

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This is how I now process source content. Only Dolby Vision content on ATV4K as LLDV.

Netflix Dolby Vision: ATV4K LLDV.
Netflix HDR10: Not Applicable since all Netflix content on ATV4K is either Dolby Vision or SDR.
Netflix SDR: ATV4K SDR.

Amazon Video Dolby Vision: ATV4K LLDV.
Amazon Video HDR10: SDR BT2020 from Panasonic UB820.
Amazon Video SDR: ATV4K SDR.

Apple TV+ Dolby Vision: ATV4k LLDV.
Apple TV+ HDR10: ATV4K HDR10.
Apple TV+ SDR: ATV4K SDR.

UHD and HD Blu-Ray discs: PC based MadVR.

HBO, Starz, YouTube.tv SDR content: ATV4K SDR.

The LLDV hack has made my ATV4K usable again. I had pretty much stopped using it because of the variable metadata injected when Dolby Vision content was converted to HDR10.
 

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ATV4K sends all HDR as Dolby Vision. There isn’t anything that’s HDR10.


Are you 100% sure? Why does the greatest showman say HDR in iTunes but others say Dolby Vision? And why when I play a Dolby vision tagged movie (Harry Potter) do I get no red tint but something with HDR tagged (greatest showman) I do? Both are from iTunes.


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Are you 100% sure? Why does the greatest showman say HDR in iTunes but others say Dolby Vision? And why when I play a Dolby vision tagged movie (Harry Potter) do I get no red tint but something with HDR tagged (greatest showman) I do? Both are from iTunes.


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I should have said “Netflix on ATV4K sends everything as Dolby Vision”.
 
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