RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream?
Is there still value in a display that is "tailor-made" for my very unique color matching functions, in your opinion? / Roger -----Original Message----- From: Max Derhak [mailto:Max.Derhak@onyxgfx.com] Sent: 28 mars 2016 12:45 To: Roger Breton <graxx@videotron.ca>; ''colorsync-users?lists. apple. com' List' <colorsync-users@lists.apple.com> Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? Using narrow primaries to discover color matching functions for an individual is different than using them to perform color reproduction with the intent that the observed appearance by multiple observers is the same. The Guild and Wright experiments resulted in multiple individualized color matching functions that were then averaged together to establish the "standard" observer. Thus the standard observer doesn't necessarily predict the color matches of individual observers - especially when narrow primaries are used. Things are much better when broad primaries are used since the slight shifts in matching functions aren’t as critical. A study of observer variability relative to narrow primaries was performed by Asano with results that can be found at (http://www.cis.rit.edu/~yxa8513/Publications/Paper_CIC2014.pdf). Max Derhak (PhD) Principal Scientist -----Original Message----- From: Roger Breton [mailto:graxx@videotron.ca] Sent: Monday, March 28, 2016 12:11 PM To: Max Derhak; ''colorsync-users?lists. apple. com' List' Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? Please excuse my ignorance, Max, but what's the difference between this type of display narrow primaries and the original 1920's Guild and Wright RGB colorimetry experiments where narrow primaries were also used, as far as observer metamerism is concerned? / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Max Derhak Sent: 28 mars 2016 09:56 To: 'colorsync-users?lists. apple. com' List <colorsync-users@lists.apple.com> Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? One of my concerns with displays having really narrow primaries is that they are subject to much greater observer metamerism (among color normal observers). The problem of measuring for calibration is compounded with the problem of getting observer agreement on appearance. Max Derhak (PhD) Principal Scientist Onyx Graphics Inc.
The display is one side of it. A perfect system for the individual requires a camera with that individual's matching functions also. -----Original Message----- From: colorsync-users-bounces+waynebretl=cox.net@lists.apple.com [mailto:colorsync-users-bounces+waynebretl=cox.net@lists.apple.com] On Behalf Of Roger Breton Sent: Monday, March 28, 2016 10:14 AM To: 'Max Derhak'; ''colorsync-users?lists. apple. com' List' Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? Is there still value in a display that is "tailor-made" for my very unique color matching functions, in your opinion? / Roger -----Original Message----- From: Max Derhak [mailto:Max.Derhak@onyxgfx.com] Sent: 28 mars 2016 12:45 To: Roger Breton <graxx@videotron.ca>; ''colorsync-users?lists. apple. com' List' <colorsync-users@lists.apple.com> Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? Using narrow primaries to discover color matching functions for an individual is different than using them to perform color reproduction with the intent that the observed appearance by multiple observers is the same. The Guild and Wright experiments resulted in multiple individualized color matching functions that were then averaged together to establish the "standard" observer. Thus the standard observer doesn't necessarily predict the color matches of individual observers - especially when narrow primaries are used. Things are much better when broad primaries are used since the slight shifts in matching functions aren’t as critical. A study of observer variability relative to narrow primaries was performed by Asano with results that can be found at (http://www.cis.rit.edu/~yxa8513/Publications/Paper_CIC2014.pdf). Max Derhak (PhD) Principal Scientist -----Original Message----- From: Roger Breton [mailto:graxx@videotron.ca] Sent: Monday, March 28, 2016 12:11 PM To: Max Derhak; ''colorsync-users?lists. apple. com' List' Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? Please excuse my ignorance, Max, but what's the difference between this type of display narrow primaries and the original 1920's Guild and Wright RGB colorimetry experiments where narrow primaries were also used, as far as observer metamerism is concerned? / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Max Derhak Sent: 28 mars 2016 09:56 To: 'colorsync-users?lists. apple. com' List <colorsync-users@lists.apple.com> Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? One of my concerns with displays having really narrow primaries is that they are subject to much greater observer metamerism (among color normal observers). The problem of measuring for calibration is compounded with the problem of getting observer agreement on appearance. Max Derhak (PhD) Principal Scientist Onyx Graphics Inc. _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/waynebretl%40cox.net This email sent to waynebretl@cox.net
On Mar 28, 2016, at 10:22 AM, Wayne Bretl <waynebretl@cox.net> wrote:
The display is one side of it. A perfect system for the individual requires a camera with that individual's matching functions also.
...and cameras are quite significantly different from humans, such that no camera I'm aware of is even close to any human. If you want to do that sort of thing at the input end, you've got to go the multi-spectral route such as what Dr. Berns and his gang at RIT do. You don't necessarily need especially exotic equipment. A standard RGB camera plus a couple carefully-selected Kodak / Wratten color filters can give you "good enough" spectral resolution. And you can use more and more filters to narrow down the spectral resolution to whatever your need is. There're academic papers freely downloadable from the RIT Web site for those interested in the details...but, in practice, it's of little interest to anybody outside of the curatorial or forensic fields. But all this misses another, more fundamental problem. So you've got something perfectly suited to your own visual system. What good is that going to be for anybody else? Somebody else is going to see differences you'll ignore, and ignore differences you might obsess over. That's a big part of the advantage in the standard observers. They're guaranteed perfect for nobody, but they're also pretty much equally "close enough" for everybody, too. ...and, again. Graphic arts isn't a precision science. Yes, 1 DE _can_ be distinguished in certain circumstances, but the error from paper that doesn't lie quite flat is typically a lot more than 1 DE. Almost no real-world environments are actually that sensitive. If your total system has a low-single-digit average DE error, if there aren't any double-digit DE errors in areas people care about, if everything is consistent edge-to-edge...there're plenty advantages to tight controls in color management past that (better shadow / highlight detail, for example), but not in areas that are going to be seen in terms of fidelity of color reproduction. Cheers, b&
You said it quite correctly. In fact, historically, color reproduction systems, such as color film, have used the trick of narrowing the spectral responses to be much sharper than any standard observer curves, in order to increase the eventual color saturation of the output. This kind of thing works quite well as long as the illumination and object reflectance spectra are reasonably broad (e.g., Color Checker chart, daylight or incandescent), failing only for special cases (like film depicting the old fluorescent lighting as greenish) or extremely narrow-spectra objects. I wrote a paper for SMPTE on limitations of wide gamut imaging that explored how narrow spectra can be before they cause trouble with narrow camera sensitivity curves. The powerpoint presentation can be downloaded here: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact... The text version from the Journal is here: http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=7269291&url=http%3A%2F... Regards, Wayne -----Original Message----- From: colorsync-users-bounces+waynebretl=cox.net@lists.apple.com [mailto:colorsync-users-bounces+waynebretl=cox.net@lists.apple.com] On Behalf Of Ben Goren Sent: Monday, March 28, 2016 10:47 AM To: 'colorsync-users?lists. apple. com' List Subject: Re: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? On Mar 28, 2016, at 10:22 AM, Wayne Bretl <waynebretl@cox.net> wrote:
The display is one side of it. A perfect system for the individual requires a camera with that individual's matching functions also.
...and cameras are quite significantly different from humans, such that no camera I'm aware of is even close to any human. If you want to do that sort of thing at the input end, you've got to go the multi-spectral route such as what Dr. Berns and his gang at RIT do. You don't necessarily need especially exotic equipment. A standard RGB camera plus a couple carefully-selected Kodak / Wratten color filters can give you "good enough" spectral resolution. And you can use more and more filters to narrow down the spectral resolution to whatever your need is. There're academic papers freely downloadable from the RIT Web site for those interested in the details...but, in practice, it's of little interest to anybody outside of the curatorial or forensic fields. But all this misses another, more fundamental problem. So you've got something perfectly suited to your own visual system. What good is that going to be for anybody else? Somebody else is going to see differences you'll ignore, and ignore differences you might obsess over. That's a big part of the advantage in the standard observers. They're guaranteed perfect for nobody, but they're also pretty much equally "close enough" for everybody, too. ...and, again. Graphic arts isn't a precision science. Yes, 1 DE _can_ be distinguished in certain circumstances, but the error from paper that doesn't lie quite flat is typically a lot more than 1 DE. Almost no real-world environments are actually that sensitive. If your total system has a low-single-digit average DE error, if there aren't any double-digit DE errors in areas people care about, if everything is consistent edge-to-edge...there're plenty advantages to tight controls in color management past that (better shadow / highlight detail, for example), but not in areas that are going to be seen in terms of fidelity of color reproduction. Cheers, b& _______________________________________________ Do not post admin requests to the list. They will be ignored. Colorsync-users mailing list (Colorsync-users@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/waynebretl%40cox.net This email sent to waynebretl@cox.net
Its not really that the display is tailor-made for your very unique color matching functions. It just means that the color management used to drive the display may need to be tuned/balanced on an individual basis, and standard XYZ colorimetry may not predict the appearance of what you actually see. If you are doing color critical work like color grading on a narrow primary monitor this becomes really important - especially when multiple observers using the monitor are involved. The appearance on the monitor can be different for each observer - without some form of observer specific correction being performed. Max Derhak (PhD) Principal Scientist -----Original Message----- From: Roger Breton [mailto:graxx@videotron.ca] Sent: Monday, March 28, 2016 1:14 PM To: Max Derhak; ''colorsync-users?lists. apple. com' List' Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? Is there still value in a display that is "tailor-made" for my very unique color matching functions, in your opinion? / Roger -----Original Message----- From: Max Derhak [mailto:Max.Derhak@onyxgfx.com] Sent: 28 mars 2016 12:45 To: Roger Breton <graxx@videotron.ca>; ''colorsync-users?lists. apple. com' List' <colorsync-users@lists.apple.com> Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? Using narrow primaries to discover color matching functions for an individual is different than using them to perform color reproduction with the intent that the observed appearance by multiple observers is the same. The Guild and Wright experiments resulted in multiple individualized color matching functions that were then averaged together to establish the "standard" observer. Thus the standard observer doesn't necessarily predict the color matches of individual observers - especially when narrow primaries are used. Things are much better when broad primaries are used since the slight shifts in matching functions aren’t as critical. A study of observer variability relative to narrow primaries was performed by Asano with results that can be found at (http://www.cis.rit.edu/~yxa8513/Publications/Paper_CIC2014.pdf). Max Derhak (PhD) Principal Scientist -----Original Message----- From: Roger Breton [mailto:graxx@videotron.ca] Sent: Monday, March 28, 2016 12:11 PM To: Max Derhak; ''colorsync-users?lists. apple. com' List' Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? Please excuse my ignorance, Max, but what's the difference between this type of display narrow primaries and the original 1920's Guild and Wright RGB colorimetry experiments where narrow primaries were also used, as far as observer metamerism is concerned? / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Max Derhak Sent: 28 mars 2016 09:56 To: 'colorsync-users?lists. apple. com' List <colorsync-users@lists.apple.com> Subject: RE: Quantum Dot Tech - cheap wide gamut but is it ready for mainstream? One of my concerns with displays having really narrow primaries is that they are subject to much greater observer metamerism (among color normal observers). The problem of measuring for calibration is compounded with the problem of getting observer agreement on appearance. Max Derhak (PhD) Principal Scientist Onyx Graphics Inc.
participants (4)
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Ben Goren
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Max Derhak
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Roger Breton
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Wayne Bretl