Metameric failure and TV calibration - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 16 Old 07-04-2019, 11:47 PM - Thread Starter
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I've been reading recently that oled and quantum dot light spectrum isn't the same as a crt, and thus it gives the perception of inaccurate colors, even when calibrated to d65. They just don't follow cie 1931. I've owned both the first quantum dot tv, the Sony w900a, and an LG c8 and they both have always looked a little off. LG even implemented a metameric mode on its OLEDs with it's Technicolor expert setting. The correct coordinates, according to LG, are 0.300, 0.327 for the white point. How is this determined? Do you measure the spectral points of the tv and put it into an equation? I'll be calibrating the Technicolor mode on the LG to that white point whenever the new update comes out. I'm not sure if metameric correction is just for SDR, or both HDR and SDR. Since developers often use the Sony oled and Dolby pulsar for HDR, one would think that cie 1931 was completely disregarded. If any of you have any thought to share I'd love to hear them. I hate thinking that most of my calibrations are ok at best.

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post #2 of 16 Old 07-05-2019, 12:17 AM
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If I can read your post correctly...

https://www.lightillusion.com/percep...our_match.html

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post #3 of 16 Old 07-05-2019, 10:49 PM
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In the consumer world RGB OLEDs don't exist. So far as I know all consumer OLEDs use the White OLED technology that LG developed.


The White OLEDs have much, much less of a problem with metameric failure compared to their RGB cousins.


The white point of 0.300, 0.327 alluded to below sounds much too extreme to me. From my observation a calibrated LG OLED appears a little too red, maybe 2 dE from D65 at most. 0.300, 0.327 is over 7 dE.
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post #4 of 16 Old 07-06-2019, 07:44 AM
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Folks state* that you need a reference next to a calibrated LED LCD and OLED to make shure the calibration is correct. Would color patters to check if colors are displayed correctly or similar not be enough checking?

*
https://www.avsforum.com/forum/139-d...-lg-oleds.html
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post #5 of 16 Old 07-06-2019, 07:20 PM - Thread Starter
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In the consumer world RGB OLEDs don't exist. So far as I know all consumer OLEDs use the White OLED technology that LG developed.


The White OLEDs have much, much less of a problem with metameric failure compared to their RGB cousins.


The white point of 0.300, 0.327 alluded to below sounds much too extreme to me. From my observation a calibrated LG OLED appears a little too red, maybe 2 dE from D65 at most. 0.300, 0.327 is over 7 dE.
I calibrated to 0.304,0.325 last night, because I read a post from Ted that said it's close to the Sony mx300. It's looks much less yellow and way better to my eye. I personally think the LG and Dolby recommended 0.308,0.312 might be what I end up with when it's all said and done. I definitely don't like d65 anymore for these sets. It's just inaccurate.
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post #6 of 16 Old 07-06-2019, 07:33 PM
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I calibrated to 0.304,0.325 last night, because I read a post from Ted that said it's close to the Sony mx300. It's looks much less yellow and way better to my eye. I personally think the LG and Dolby recommended 0.308,0.312 might be what I end up with when it's all said and done. I definitely don't like d65 anymore for these sets. It's just inaccurate.
My eyes report something very different. This is not metameric failure. It is the normal variation between different observers.

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post #7 of 16 Old 07-06-2019, 08:31 PM - Thread Starter
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I calibrated to 0.304,0.325 last night, because I read a post from Ted that said it's close to the Sony mx300. It's looks much less yellow and way better to my eye. I personally think the LG and Dolby recommended 0.308,0.312 might be what I end up with when it's all said and done. I definitely don't like d65 anymore for these sets. It's just inaccurate.
My eyes report something very different. This is not metameric failure. It is the normal variation between different observers.
Thank you for your explanation Tom. I've been reading your stuff for years, and I completely respect your opinion on the subject. So now that I've said that, with your experience, you don't see an overly yellow tint at d65 with the OLEDs? I'm sure you've seen many more reference monitors, particularly crt, and it doesn't look off to you? The only basis I have for comparison is an older dlp, by brothers old CRT that I calibrated, and numerous ccrt lcds. They all look different to my eye when calibrated. My old Sony w900a, which I believe is the first commercial quantum dot tv, and my oled look way off. I use a spectro that I recently got recertified by x-rite, so I know it's accurate.
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post #8 of 16 Old 07-06-2019, 08:42 PM
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Thank you for your explanation Tom. I've been reading your stuff for years, and I completely respect your opinion on the subject. So now that I've said that, with your experience, you don't see an overly yellow tint at d65 with the OLEDs? I'm sure you've seen many more reference monitors, particularly crt, and it doesn't look off to you? The only basis I have for comparison is an older dlp, by brothers old CRT that I calibrated, and numerous ccrt lcds. They all look different to my eye when calibrated. My old Sony w900a, which I believe is the first commercial quantum dot tv, and my oled look way off. I use a spectro that I recently got recertified by x-rite, so I know it's accurate.
No, not at all. If you see something as yellowish, that means that you are expecting something bluer and you are not getting it. OLEDs look slightly too red to me, but very slightly.


You can test this objectively. Calibrate a monitor that is known to NOT suffer from metameric failure with the most accurate instrument you have. A normal computer monitor is a good choice. Once you have done this, put the monitor and the OLED in full field mode displaying a white test pattern at, say, 60%. Now just adjust the OLED until it visually matches the computer monitor.


BTW, there is something weird about the settings on your computer. The letter 's' is being displayed as s and capital 'S' is displayed as S

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post #9 of 16 Old 07-06-2019, 09:01 PM - Thread Starter
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Thank you for your explanation Tom. I've been reading your stuff for years, and I completely respect your opinion on the subject. So now that I've said that, with your experience, you don't see an overly yellow tint at d65 with the OLEDs? I'm sure you've seen many more reference monitors, particularly crt, and it doesn't look off to you? The only basis I have for comparison is an older dlp, by brothers old CRT that I calibrated, and numerous ccrt lcds. They all look different to my eye when calibrated. My old Sony w900a, which I believe is the first commercial quantum dot tv, and my oled look way off. I use a spectro that I recently got recertified by x-rite, so I know it's accurate.
No, not at all. If you see something as yellowish, that means that you are expecting something bluer and you are not getting it. OLEDs look slightly too red to me, but very slightly.


You can test this objectively. Calibrate a monitor that is known to NOT suffer from metameric failure with the most accurate instrument you have. A normal computer monitor is a good choice. Once you have done this, put the monitor and the OLED in full field mode displaying a white test pattern at, say, 60%. Now just adjust the OLED until it visually matches the computer monitor.


BTW, there is something weird about the settings on your computer. The letter 's' is being displayed as s and capital 'S' is displayed as S
I have a new cellphone. I've been noticing weird characters on the site. I was wondering if it was just me lol. I guess I mean overly red. It's extremely hard to describe the colors you're seeing, and I can understand how observer metamerism is at play. This document outlines the Dolby and LG recommended white point for OLEDs to match a reference CRT. What's your opinion on this?
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post #10 of 16 Old 07-07-2019, 07:45 PM
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I have a new cellphone. I've been noticing weird characters on the site. I was wondering if it was just me lol. I guess I mean overly red. It's extremely hard to describe the colors you're seeing, and I can understand how observer metamerism is at play. This document outlines the Dolby and LG recommended white point for OLEDs to match a reference CRT. What's your opinion on this?
Do you have a link to the full document?

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post #11 of 16 Old 07-08-2019, 12:17 PM - Thread Starter
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I have a new cellphone. I've been noticing weird characters on the site. I was wondering if it was just me lol. I guess I mean overly red. It's extremely hard to describe the colors you're seeing, and I can understand how observer metamerism is at play. This document outlines the Dolby and LG recommended white point for OLEDs to match a reference CRT. What's your opinion on this?
Do you have a link to the full document?
It was shared to my by Ted from lightspace. This is where you can access it.


https://www.researchgate.net/publication/325489575_78-1_Correcting_Metameric_Failure_of_Wide_Color_Gamut _Displays

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post #12 of 16 Old 07-10-2019, 02:11 AM
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It was shared to my by Ted from lightspace. This is where you can access it.


https://www.researchgate.net/publication/325489575_78-1_Correcting_Metameric_Failure_of_Wide_Color_Gamut _Displays
The document is behind a pay wall, so I cannot access it.

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post #13 of 16 Old 07-10-2019, 08:02 AM
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Then, someone can explain why a company of such prestige as Technicolor, recommends the white point that they have pre-established in the LG oled of 2018 and 19. I understand then that in case of not having the tools nor the knowledge to establish an alternative white point , it is better to stay with warm 2 in a LG c8 ???
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post #14 of 16 Old 07-11-2019, 05:11 PM - Thread Starter
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Originally Posted by chronitis View Post
It was shared to my by Ted from lightspace. This is where you can access it.


https://www.researchgate.net/publication/325489575_78-1_Correcting_Metameric_Failure_of_Wide_Color_Gamut _Displays
The document is behind a pay wall, so I cannot access it.
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Send me a PM with your email and I'll send it to you.
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post #15 of 16 Old 07-11-2019, 05:14 PM - Thread Starter
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Then, someone can explain why a company of such prestige as Technicolor, recommends the white point that they have pre-established in the LG oled of 2018 and 19. I understand then that in case of not having the tools nor the knowledge to establish an alternative white point , it is better to stay with warm 2 in a LG c8 ???
They're matching to a Xenon projector, which I believe was calibrated via Judd Voss. I could be totally wrong, but the point is it's not as accurate as it could be. It's very close to Tyler's recommended .304,.325, and it does look good once calibrated to the correct coordinates. Just not as good as the LG and Dolby recommended .308, .313 IMO
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post #16 of 16 Old 07-12-2019, 01:10 AM
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I personally think that the alternative white point Technicolor, is better than the classic D65 in an Oled C8, I have made comparisons with for example another oled LG 930 V of 2 generation calibrated to D65 and the C 8 with Technicolor and the image is quite similar. In case of not having the necessary tools or calibration knowledge, I think that Technicolor is preferable and more accurate. The C8 to D65 leaves skin tones very exaggeratedly red, the image is completely red and unnatural. Every time I have more clear that these televisions have a very remarkable Metameric failure.
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