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post #31 of 89 Old 10-20-2014, 04:30 AM
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Sony had a problem with the narrow spectrum of its green and red quantum dots.
I used that as an analogy to the problem of yellow in Quattrons.
Colorimeters are not equally sensitive to all spectra. The cost would be prohibitive.
Most are set up to examine output from RGB devices, which means all other color ranges
of the spectrum are either ignored or rolled into one of the primaries.
You don't care about Quattron and the problems of machine-calibration. Fair enough.
But you are putting out far more heat than light on the subject.
This forum is rife with examples of colorimeters lacking profiles for certain output ranges.
People are sharing info and creating their own profiles, particularly on the Sony Quantum Dot post.
Since there is a phobia against Quattron, calibrations are left to hacks like me, who use the
calibration discs to set up white and black and white temps without the mathematics. Pity us...
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post #32 of 89 Old 10-20-2014, 05:53 AM
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Quote:
Originally Posted by johnfull View Post
Colorimeters may miss
part of the output by having a peak sensitivity other than the specific wavelength emitted.
This lends credence to the idea that the yellow output of a Quattron is missed by colorimeters
that are sensitive in the red and the green, but not between.
Why do you think colorimeters are any more or less sensitive to specific colors than you are? Colorimeters are sensitive to the entire spectrum, just like your eyes.
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post #33 of 89 Old 10-20-2014, 06:06 AM
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Quote:
Originally Posted by zoyd View Post
Why do you think colorimeters are any more or less sensitive to specific colors than you are? Colorimeters are sensitive to the entire spectrum, just like your eyes.
Not all eyes are created equal and neither are all colorimeters.
Why would a manufacturer spend the money required for sensitivity
to all frequencies when only red, green, and blue are usually needed?
Human vision is not as simple as you claim either, by the way...
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post #34 of 89 Old 10-20-2014, 06:53 AM
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Quote:
Originally Posted by johnfull View Post
Sony had a problem with the narrow spectrum of its green and red quantum dots.
I used that as an analogy to the problem of yellow in Quattrons.
Colorimeters are not equally sensitive to all spectra. The cost would be prohibitive.
Most are set up to examine output from RGB devices, which means all other color ranges
of the spectrum are either ignored or rolled into one of the primaries.
You don't care about Quattron and the problems of machine-calibration. Fair enough.
But you are putting out far more heat than light on the subject.
This forum is rife with examples of colorimeters lacking profiles for certain output ranges.
People are sharing info and creating their own profiles, particularly on the Sony Quantum Dot post.
Since there is a phobia against Quattron, calibrations are left to hacks like me, who use the
calibration discs to set up white and black and white temps without the mathematics. Pity us...
By reading the numerous postings that you have made, I am having some difficulty following and/or agreeing with your logic.

First, when you reference colorimeter's inability to read various colors I would say, "I can't agree". I feel that the colorimeters work but it is the display that is the cause of the issue. With Sharp's introduction of trying to include a secondary color as a primary has introduce an array of issues. In many opinions this is a bad design. Even with LG's OLED display, LG 55EC9300 with the introduction of a white sub-pixel maybe questionable. This LG display is so plagued with issues of bad designing I would highly recommend, "Run ! , don't walk from this display". IF you look at displays and the issues revolving around them you will always find that the fault is not with the meter but with the engineering of the display. For what ever reason you wish to come up with, "Brain Farts" with the adding of sub-pixels or "Delusions of Adequacy" with regards of making the controls function as they should, the fault seems to always lay with the manufacturer. I have been around long enough to see many ideas from the manufacturers come and go and as for Quantum Dots, the jury is still out. This concept is still filled with a lot of issues. For all in all, the meters work and the science and engineering is sound. Due to the bad engineering of displays a secondary market and product has emerged; Video Processors. These little black boxes are designed to correct the inefficiency of the display. If the displays were designed properly these so called black boxes would be of little value.

The major problems with colorimeters is when individuals use them without profiling them against a spectrometer. You use the term "Phobia", I would use the term "Cautious".

As with most threads, this thread has been high-jacked away from robarivas. Did anyone really answer his question? We all owe him an apology. Instead, individuals come out of the woodwork to argue over non-related subjects like the color of red instead of assisting the one who is in need of assistance.
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post #35 of 89 Old 10-20-2014, 07:00 AM
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Quote:
Originally Posted by johnfull View Post
Not all eyes are created equal and neither are all colorimeters.
Why would a manufacturer spend the money required for sensitivity
to all frequencies when only red, green, and blue are usually needed?
Human vision is not as simple as you claim either, by the way...
I didn't say either of those things. I was just telling you how colorimeters are designed. Any perceived errors that result from using a colorimeter are a function of how different your vision is from the standard observer and how different the colorimeter filter functions are from the standard observer, and have nothing to do with an imaginary lack of sensitivity to yellow. These perceptual errors are accentuated by displays with narrow spectral peaks, this is a well known issue in colorimetry.
@robarivas - You should always minimize dE, so whichever trade-off between gamma and chromaticity achieves lowest dE is preferred.

Last edited by zoyd; 10-20-2014 at 07:04 AM.
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post #36 of 89 Old 10-20-2014, 07:12 AM
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Cool

The major problems with colorimeters is when individuals use them without profiling them against a spectrometer. You use the term "Phobia", I would use the term "Cautious".

As with most threads, this thread has been high-jacked away from robarivas. Did anyone really answer his question? We all owe him an apology. Instead, individuals come out of the woodwork to argue over non-related subjects like the color of red instead of assisting the one who is in need of assistance.[/QUOTE]

I offered my quasi-calibration of my own Quattron sets (2) and
he respectfully declined, saying that out of the box is better than
trying to adjust with a calibration disc, but without a colorimeter
and software. He and I disagree on that point and I have more
than a dozen folks who have used my settings with satisfaction.
Meantime, the priest class continues to defend the status quo,
even though it stifles innovation and refuses help with what is
already on the market. Backlight quality is my biggest complaint
with modern LCD displays. Back to CCFL, I would say, but that
puts me in your camp of stifling innovation.
Sharp shrewdly dropped the wide gamut claim when backlight
quality fell, just as they were introducing Quattron. Bad timing!
They switched to claiming better yellows (false) and brighter
whites (true), thanks to the efficiency of phosphor emission filtering.
I would prefer less brightness and more gamut, but that's just me.
As for crawling out of the woodwork, I have been a participating
AVS member for many years, thanks.
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post #37 of 89 Old 10-20-2014, 07:36 AM
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"...Any perceived errors that result from using a colorimeter are a function of how different your vision is from the standard observer and how different the colorimeter filter functions are from the standard observer, and have nothing to do with an imaginary lack of sensitivity to yellow. These perceptual errors are accentuated by displays with narrow spectral peaks, this is a well known issue in colorimetry."

So, to choose a medium-hi white temperature setting and
smooth out the humps of discoloration with either a 2-point
or a 10-point adjustment is not at all recommended?
I haven't seen a calibration from a colorimeter that comes close
to the clean white that can be generated with the eye on these sets.
Three different folks have posted colorimeter/software calibrations
and all but one of more than a dozen users prefer my settings to
those. Theirs result in a yellowed-white. No one is answering why
the results come out wrong! I would prefer to set up my Movie
setting with 10 Point, properly calibrated and have fudged the
results of those guys' settings with a bit of blue to decent effect.
But then there is the fleshtone problem which they don't even
begin to solve and they resort to turning the Global Tint control (!).
The Quattron sets have been out for 5 years and the calibration
community has preferred to malign rather than to innovate. It's what
comes when innovation is from a relatively small player and is not
adopted by more. It doesn't mean it's not a good innovation but
simply that the market weeds out innovations all the time.
Sharp was a pioneer in flat screens, just as a reminder...
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post #38 of 89 Old 10-20-2014, 09:45 AM
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Quote:
Originally Posted by johnfull View Post

So, to choose a medium-hi white temperature setting and
smooth out the humps of discoloration with either a 2-point
or a 10-point adjustment is not at all recommended?
I haven't seen a calibration from a colorimeter that comes close
to the clean white that can be generated with the eye on these sets.
However you deal with perceived problems generated by your colorimeter calibration is of course up to you since it is no longer in the realm of calibration. My comment was only to correct your misinformed view of where the problems originate from. Colorimeters will register a signal for any normally visible color in the spectrum, they are not limited to R,G,B areas of the gamut. If the Quattron has generally agreed upon perceivable errors even though the colorimeter says it doesn't, it's because of the shape of the entire spectrum and not which colors were chosen as primaries.
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post #39 of 89 Old 10-20-2014, 10:02 AM
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Or it could be what the software does with that data -- if the colorimeter puts out numbers
for the three primaries, what does it put out for yellow? And how is that figured into the
calculation with the vectors? Yellow will definitely make white light mixed with blue, so the
mis-application of the yellow data could still give a false reading that blue is too intense.
Right? SOMETHING is making the SpectraCals read yellow whites and green fleshtones!
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post #40 of 89 Old 10-20-2014, 10:06 AM - Thread Starter
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Thanks to all responses thus far. While there has been a side discussion going on I'm nevertheless appreciative. 2 responses really stood out for me and I have some follow-up questions/comments on those as follows:


1) john stephens: I really appreciate the hyperlink. And I do think that if I shoot for a different white point, the answers about what to do with the primaries and how to do it are contained in that link. However, I must admit that the content is too far above my head for me to put it to practical use (even with the matrix for D65 to D75 already laid out). Furthermore, I have not heard a great deal of support thus far for choosing a different white point. Indeed I'm wondering if the only value of increasing the white point is to make charts look better.


2) zoyd: Your response about always minimize dE is attractively simple. However, if that is the best course of action then which dE should I be looking to minimize? HCFR has three: "without gamma", "Relative Y", and "with gamma". Using D65 as my white point, I can often get "without gamma" and "Relative Y" dE's below 3. But, using D65, my "with gamma" dE is always above 5 and sometimes as high as 9 or 10.
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post #41 of 89 Old 10-20-2014, 10:58 AM
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Quote:
Originally Posted by robarivas View Post
2) zoyd: Your response about always minimize dE is attractively simple. However, if that is the best course of action then which dE should I be looking to minimize? HCFR has three: "without gamma", "Relative Y", and "with gamma". Using D65 as my white point, I can often get "without gamma" and "Relative Y" dE's below 3. But, using D65, my "with gamma" dE is always above 5 and sometimes as high as 9 or 10.
ok, my comment was more for general color calibration. In your case regarding the grayscale I agree with HDTVChallenged that chromaticity (the "without gamma" option) is first priority. Then if you can't reproduce the correct gamma tracking, I don't think changing your white point target will help you. Do you have gamma adjustments? What is your target function? Since the transfer function standard itself has not been well defined in the past and since environment plays a role, perhaps you are being too restrictive as to what would be acceptable.
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post #42 of 89 Old 10-20-2014, 12:36 PM
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couldn't one make the argument that since

1) there may be a degree of chromatic adaptation, but no "gamma" adaptation

and

2) having the wrong gamma may actually render details invisible, or introduce visible artifacts

that one should sacrifice a bit of accuracy for which particular white point you calibrate to (assuming a consistent grayscale), to gain a more accurate gamma?
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post #43 of 89 Old 10-20-2014, 01:14 PM - Thread Starter
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Quote:
Originally Posted by zoyd View Post
ok, my comment was more for general color calibration. In your case regarding the grayscale I agree with HDTVChallenged that chromaticity (the "without gamma" option) is first priority. Then if you can't reproduce the correct gamma tracking, I don't think changing your white point target will help you. Do you have gamma adjustments? What is your target function? Since the transfer function standard itself has not been well defined in the past and since environment plays a role, perhaps you are being too restrictive as to what would be acceptable.
I'm using 10 point white balance controls but other than a gamma slider (which I've already maxed/min'd out to help boost my gamma number) I have no separate gamma controls. The target function I'm using is BT. 1886 in the HCFR default configuration. Also, for whatever its worth, when I've experimented with a higher white point, my gamma number shot way up closer to the target (from as low as 1.7 in some attempts all the way to 2.2).
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post #44 of 89 Old 10-20-2014, 01:28 PM
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With 10 pt RGB controls you should be able to get close to the gamma curve you want by raising/lowering all three at the same time at each stimulus level. Usually gamma and white point are not coupled but maybe your display is not typical. Also, sometimes a low gamma average is due to a too high contrast setting.
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post #45 of 89 Old 10-20-2014, 02:06 PM - Thread Starter
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You are correct that the gamma would fall in line to target by lowering all 3 colors (R, G, and B). But the core issue with this display is that at D65 I run out of blue (across all 10 IREs by the way), meaning I can't lower blue any further to get gamma in line. I could lower red and green, which will help with gamma, but then my chromaticity would be out of whack (e.g., think red and green at 94% and blue at 115%). This is the tradeoff. Possible solutions are (1) to get into the service menu to potentially change some setting that would effectively expand my blue range on the minus side, (2) decide on some tradeoff between chromaticity and gamma, or (3) increase my white point.


My contrast tracks the greyscale correctly at its current setting, meaning that changes to, say for example, point 8 on my 10 point control show up on the grey scale step pattern in the actual 80 IRE step rather than step 70, 75, 85 or 90. If I were to change my contrast then my tracking would be off.
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post #46 of 89 Old 10-20-2014, 02:51 PM
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What happens if you increase RGB of the 2pt, does that give you a better adjust range for gamma? Or a different gamma slider position?
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post #47 of 89 Old 10-20-2014, 03:14 PM - Thread Starter
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My display ignores the 2 point if I use 10 point and vice versa. I understand other displays let you use 2 point to "rough in" the calibration but mine does not. If I were to move the gamma slider to another position my gamma would be even worse.
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post #48 of 89 Old 10-20-2014, 03:17 PM
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Quote:
Originally Posted by johnfull View Post
The disturbance comes from not adding the spectral yellow to
the calculation of white. The calculation will show excesss blue.
Other functions of the yellow are handled by the chroma circuit,
which substitutes the yellow pixel for some of the R+G LUT.
Thought #1 : So in other words you're saying that the yellow sub-pixel is *not* being "fired" when white is being displayed? Just the R,G, and B sub-pixels? Again, having trouble following your logic.

Thought #2 : A spectro will include *everything* it sees (including the yellow) in the calculation of "white." There's nothing special about white ... or yellow.

Thought #3 : All I'm getting from your statement translates to 'Sharp completely broke the HDTV/R.709 color system, therefore it must be the (colori)meter's fault that it doesn't see the Quattron "correctly."'

I give up ...
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post #49 of 89 Old 10-20-2014, 03:26 PM
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Quote:
Originally Posted by robarivas View Post

My contrast tracks the greyscale correctly at its current setting, meaning that changes to, say for example, point 8 on my 10 point control show up on the grey scale step pattern in the actual 80 IRE step rather than step 70, 75, 85 or 90. If I were to change my contrast then my tracking would be off.
This might be preferable to a higher white point, how much of a contrast hit do you have to take to get a reasonable gamma response? Working around misalignment of the 10 pt controls is a pain but it is doable, you should also be able to adjust sub-contrast in the service menu to realign.
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post #50 of 89 Old 10-20-2014, 03:54 PM
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Quote:
Originally Posted by HDTVChallenged View Post
Thought #1 : So in other words you're saying that the yellow sub-pixel is *not* being "fired" when white is being displayed? Just the R,G, and B sub-pixels? Again, having trouble following your logic.

Thought #2 : A spectro will include *everything* it sees (including the yellow) in the calculation of "white." There's nothing special about white ... or yellow.

Thought #3 : All I'm getting from your statement translates to 'Sharp completely broke the HDTV/R.709 color system, therefore it must be the (colori)meter's fault that it doesn't see the Quattron "correctly."'

I give up ...
Thought #1 -- The yellow pixel is advertised as adding to brightness.
The phosphor on the blue LED has a lot of yellow wavelength light,
so it is exploited in combination with the blue light. The yellow is not
controllable from the white temperature adjustments -- which means
other adjustments have to pivot around its output.

Thought #2 -- Ok, you kill off my theory of what goes wrong when
guys with colorimeters seek out the lowest (reddest) setting and
then remove maximal blue and still complain that their readings are
too high on blue, despite having obviously trashed the white into the
yellow and the fleshtones into the green. What is your theory of why
this is happening? Saying that the yellow wavelength is foreign to a
RGB program is nothing radical. Ok, it's Sharp's 'fault' for using a
color that colorimeter makers do not acknowledge.
The tail is wagging the dog here, with calibrators telling manufacturers what
to do with their research and the materials available on the market.
It is shrewd to use yellow to counteract the blue of the LED, but it
would be better to have a balanced backlight, in my opinion.
Meantime, what do you think is driving the colorimeters crazy about
the Sharps? If there were that much excess blue in the picture, it
would be obvious. Going into a BestBuy, the Quattrons are no more
garish blue than all the other LED-backlit LCD screens. Why does the
colorimeter say otherwise?
Thought #3 -- Sharp has done little more than exploit the yellow
phosphor to counteract the industrial-strength blue LED to give some
brightness boost. The primaries are NOT outside the norms by any
significant amount. They had promised to move the green deeper
into the colorspace and use yellow to compensate, but the blue LED
has scotched that idea for now. Instead, yellow merely counteracts
blue. But the colorimeter doesn't see it, or so it seems.
Meantime, I got my set looking quite splendid, and shared my
settings far and wide to overwhelming acclaim (thank you, thank you) and I'm really just interested in your idea of what is going wrong
with the calibration tools on these sets 5 years into their existence.
The snark, I can do without...
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post #51 of 89 Old 10-20-2014, 05:23 PM
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Quote:
Originally Posted by robarivas View Post
Thanks to all responses thus far. While there has been a side discussion going on I'm nevertheless appreciative. 2 responses really stood out for me and I have some follow-up questions/comments on those as follows:


1) john stephens: I really appreciate the hyperlink. And I do think that if I shoot for a different white point, the answers about what to do with the primaries and how to do it are contained in that link. However, I must admit that the content is too far above my head for me to put it to practical use (even with the matrix for D65 to D75 already laid out). Furthermore, I have not heard a great deal of support thus far for choosing a different white point. Indeed I'm wondering if the only value of increasing the white point is to make charts look better.


2) zoyd: Your response about always minimize dE is attractively simple. However, if that is the best course of action then which dE should I be looking to minimize? HCFR has three: "without gamma", "Relative Y", and "with gamma". Using D65 as my white point, I can often get "without gamma" and "Relative Y" dE's below 3. But, using D65, my "with gamma" dE is always above 5 and sometimes as high as 9 or 10.
See FSI's discussion of using a Perceptual approach to calibrating some of these new technology based displays. Proper setting of the white point is key to all subsequent analysis. Browse to their web site and consult with some real Color Theory Physicists!
To get started, read this attached .PDF from FSI:

Last edited by john stephens; 10-20-2014 at 05:28 PM. Reason: Add content.
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post #52 of 89 Old 10-20-2014, 05:41 PM
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Apparently the attachment did not take. it was apparently too large. Browse, instead, to this site to get started:

http://www.lightillusion.com/percept...our_match.html
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post #53 of 89 Old 10-20-2014, 10:18 PM
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Quote:
Originally Posted by johnfull View Post
Thought #2 -- Ok, you kill off my theory of what goes wrong when
guys with colorimeters seek out the lowest (reddest) setting and
then remove maximal blue and still complain that their readings are
too high on blue, despite having obviously trashed the white into the
yellow and the fleshtones into the green. What is your theory of why
this is happening?
Starting with a colorimeter instead of spectro is probably mistake #1 .

Colorimeters "see" (more or less directly) in X,Y,Z (not R,G,B.) Spectroradiometers/photometers "see" radiant/spectral energy divided into individual bands ... which is converted to (X,Y,Z) ... which is still not (R,G,B.)

The simplest explanation for your observation would be that the colorimeter has not been properly profiled for the display. You have yet to produce any findings from a spectroradiometer/photometer, so I can't make any conclusion here.

The next hypothesis would be that the Quattron system is doing very strange things with the color system, such that it is no longer linear nor additive.

All that being said, IIRC, I'm sure Chad B. managed to beat at least one Quattron (mostly) into submission ... then again he has a Jeti in his tool box.
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post #54 of 89 Old 10-21-2014, 02:11 AM
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Thanks for your patience. I don't use the mathematical terms, it is true.
This thread has calibrations from a guy named Mechman and another guy, named Rlindo:
2014 Sharp AQUOS Line-Up
They both have posted SpectraCal results, but I would have to dig them out of the thread.
They and others have followed their equipment down a rabbit hole where they remove all
the blue from the signal and still report outrageously high temperature readings.
The fellow who started the current thread is going the same route, which is why I am concerned.
The suggestion to use the 'Perceptual Approach' seems very wise here!
With a lot of patience and the grayscale ramps from the AVS Forum calibration disc, I was
able to find the most neutral settings to begin with and to do the least modification to them
to achieve a good white point. Leaving blue alone, the green and red can be raised and
lowered to achieve neutral gray across the brightness continuum. Then, on to the CMS
calibrations to eliminate clipping and restore balance. Finally, a tweak of the white temp
to improve fleshtones across sources, namely, one notch of red in the Hi range added.
Using a term like 'Perceptual Approach' and saying that new technologies may require it
seems to show a crisis in the calibration community, no? I'm happy enough to spend hours
on my own set, but if I did this for a living, I would be thrown out of my customer's house
after the first week or so! Seriously, the Quattron is just a harbinger of weirdness to come...
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post #55 of 89 Old 10-21-2014, 09:15 AM
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I dont think the problem lies in the hardware or software....color is a phenomena that only exists in the brain relative to how the rods/cones react to stimuli so its not as if the meters see or even know what yellow is. Same for software. Why create this awesome mathematical engine and cut out yellow (not even sure if it works that way)? I think that the meter/sw read white according to the "old" standards but the newer displays are exciting rods/cones in ways not taken into account...ie:human vision is a lil more complex than previously thought.
Also, it might be time to start the 21XX standard observer tests for some new black magic voodoo....

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post #56 of 89 Old 10-21-2014, 10:16 AM
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I'm still hoping for a back-to-the future solution -- ultraviolet LEDs exciting the old CCFL
wide-gamut phosphors -- till something better comes along. Fluroescent tube technology
is about 100 years old these days. None of the blue LED/phosphor setups can match it...
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post #57 of 89 Old 10-21-2014, 03:01 PM
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Quote:
Originally Posted by johnfull View Post
Seriously, the Quattron is just a harbinger of weirdness to come...
It's not only instruments that will show wide variation if poor primaries are chosen - different observers will disagree as to what the picture looks like as well! There is a tradeoff between gamut size and color "robustness".
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post #58 of 89 Old 10-21-2014, 03:23 PM
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Quote:
Originally Posted by nodixe View Post
I dont think the problem lies in the hardware or software....color is a phenomena that only exists in the brain relative to how the rods/cones react to stimuli so its not as if the meters see or even know what yellow is. Same for software. Why create this awesome mathematical engine and cut out yellow (not even sure if it works that way)? I think that the meter/sw read white according to the "old" standards but the newer displays are exciting rods/cones in ways not taken into account...ie:human vision is a lil more complex than previously thought.
Also, it might be time to start the 21XX standard observer tests for some new black magic voodoo....
Actually, I went back and re-read Chad B.'s Quattron reviews over at the site formerly known as clevelandplasma-dot-com and he saw the same color luminance issues with his own two peepers as his i1Pro saw ... so ...

Interestingly, he didn't seem to have any trouble dialing in the greyscale and gamma with his i1Pro, it was the CMS that tried to open up the subspace channel(s) to V'ger.

Remember: ROYG(C)BIV ... if this were a spectral "range" issue the problem(s) would be at either the R or "BIV" ends of the spectum ... not at Y(ellow.)

So that leaves us with either Standard Observer issues, or wierdness (i.e. non-linearity) in the Quattron's color processing.

It's *possible* that the meters are actually seeing more blue(indigo,violet) energy from the "blue-LED" backlight than our eyes do ... It's far less likely that the meters would somehow "miss" the extra yellow spectral energy. Of course, this is just my crackpot hypothesis ... take it for the $0.02 that it's worth.

PS: I'm pretty sure this topic (current meters vs. wider-gamuts) has been thrashed to death more than a few times.
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post #59 of 89 Old 10-21-2014, 03:34 PM
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It's not only instruments that will show wide variation if poor primaries are chosen - different observers will disagree as to what the picture looks like as well! There is a tradeoff between gamut size and color "robustness".
The chicken and egg problem is that content developers won't
expand if hardware and calibration technicians won't follow.
Given the right backlight source, Quattron could hold the red and
blue primaries at an ideal and use yellow to allow deeper green.
That was what I thought I was buying 3 years ago, only to find
out that an indigo/blue LED is driving the whole blunderbus.
Sony had the same problem with Quantum Dots feeding off the
inappropriate blue. A warmer (longer wavelength) blue is needed
to improve the mid-wavelengths. The blue is the poorly chosen
primary on all those glowing panels on big box store walls...
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post #60 of 89 Old 10-21-2014, 03:39 PM
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Quote:
Originally Posted by HDTVChallenged View Post
Actually, I went back and re-read Chad B.'s Quattron reviews over at the site formerly known as clevelandplasma-dot-com and he saw the same color luminance issues with his own two peepers as his i1Pro saw ... so ...

Interestingly, he didn't seem to have any trouble dialing in the greyscale and gamma with his i1Pro, it was the CMS that tried to open up the subspace channel(s) to V'ger.

Remember: ROYG(C)BIV ... if this were a spectral "range" issue the problem(s) would be at either the R or "BIV" ends of the spectum ... not at Y(ellow.)

So that leaves us with either Standard Observer issues, or wierdness (i.e. non-linearity) in the Quattron's color processing.

It's *possible* that the meters are actually seeing more blue(indigo,violet) energy from the "blue-LED" backlight than our eyes do ... It's far less likely that the meters would somehow "miss" the extra yellow spectral energy. Of course, this is just my crackpot hypothesis ... take it for the $0.02 that it's worth.

PS: I'm pretty sure this topic (current meters vs. wider-gamuts) has been thrashed to death more than a few times.
Grayscale is improved by using B+Y for a large portion of the
monochrome image. Having only two variables makes it much
cleaner. I think that the blue LED is fooling either our eyes or
the instruments designed to serve our eyes (who is boss?).
I jumped into the fray with a calibrator over the yellow results
on another brand without the yellow pixel, so you are probably
right that it is the blue, one being the complement of the other,
I'm hoping for a breakthrough better excitor -- maybe ultraviolet
LEDs to drive Quantum Dots. First, we have to curve all the
screens, though...
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