January 2020 - colorsync-users

RE: Dell UP2516D
by graxx＠videotron.ca 08 Jan '20

08 Jan '20

That DIN099c color space looks weird to me. It's still an a/b diagram, though. "More" technical stuff to read about? / Roger -----Original Message----- From: colorsync-users <colorsync-users-bounces+graxx=videotron.ca(a)lists.apple.com> On Behalf Of Wire ~ via colorsync-users Sent: Wednesday, January 8, 2020 6:55 PM To: 'colorsync-users?lists.apple.com' List <colorsync-users(a)lists.apple.com> Subject: Dell UP2516D I added a DIN099c gamut plot for the Dell in native mode with sRGB, Adobe RGB and DCI-P3 D65 overlaid. https://drive.google.com/open?id=1DSpUzIAgxsiG8qi8FKr2uJ5_P4MNmTKu There are several variations for DIN99 in the DisplayCal ICC Profile Info program, I chose the one that looked the most symmetrical — haha, idiot alert! When I consider MacAdam idea of weighting, DIN99 looks like it preserves some other sort of distance over perceptual distance? But I'm no cartographer any more so than I am a color scientist. I would appreciate hearing any ideas about why this plot is shaped as such. Pls appreciate the beauty of Dell's gamut coverage compared to popular spaces. In native mode, the display can do pre-press and cinema, as well as "sRGB-2020" :) _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx(a)videotron.ca

1 0

RE: Printer - RBB or CMYK?
by graxx＠videotron.ca 08 Jan '20

08 Jan '20

David, Perhaps only the more "expensive" color laser printers actually have a native CMYK driver? My experience with the tabloid Xeroxes of this world has always been one where, once I turn off color management (or correction) in the Printer's Preferences, I had a clear (but not always stable) CMYK output path. My experience 😊 / Roger -----Original Message----- From: colorsync-users <colorsync-users-bounces+graxx=videotron.ca(a)lists.apple.com> On Behalf Of David Wollmann via colorsync-users Sent: Wednesday, January 8, 2020 6:30 PM To: ColorSync <colorsync-users(a)lists.apple.com> Subject: Re: Printer - RBB or CMYK? In my experience most Laser printers expect to receive RGB data. It’s easy to print a standard test target in RGB and CMYK and evaluate the results, usually the RGB shows smoother prints with better gamut. Sending a black target as you describe is full of things to trip over while trying to maintain a single color black. If sending from Adobe products such as InDesign or Illustrator what are your Appearance of Black Preferences set to? Does it treat all blacks accurately or does it send Rich blacks out? If creating a PDF how are you managing blacks and color conversions, is the pdf even tagged? Many factors can alter your single color blacks before it gets to the printer. Check with the manufacturer, often it can be found on a web site. David Wollmann > On Jan 8, 2020, at 3:47 PM, colorsync-users-request(a)lists.apple.com wrote: > > From: PPS Lists <lists(a)precisionpixelstudios.com <mailto:lists@precisionpixelstudios.com>> > > I used to know how to do this but it has been so long since I have needed to I have forgotten how. > > I need to determine if the print pipeline for a certain laser printer is RGB or CMYK. I used to know how to spin up a Photoshop file in a certain way and send to print. > > IIRC, the procedure was along the lines of make a CMYK document, and create a black square of equal parts of Cyan, Magenta and Yellow. Then slap a smaller 100% black square on top of the CMY square and send to print. Something like that. > > Does anyone know the correct steps? > > Thank you. _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx(a)videotron.ca

1 0

Dell UP2516D
by Wire ~ 08 Jan '20

08 Jan '20

I added a DIN099c gamut plot for the Dell in native mode with sRGB, Adobe RGB and DCI-P3 D65 overlaid. https://drive.google.com/open?id=1DSpUzIAgxsiG8qi8FKr2uJ5_P4MNmTKu There are several variations for DIN99 in the DisplayCal ICC Profile Info program, I chose the one that looked the most symmetrical — haha, idiot alert! When I consider MacAdam idea of weighting, DIN99 looks like it preserves some other sort of distance over perceptual distance? But I'm no cartographer any more so than I am a color scientist. I would appreciate hearing any ideas about why this plot is shaped as such. Pls appreciate the beauty of Dell's gamut coverage compared to popular spaces. In native mode, the display can do pre-press and cinema, as well as "sRGB-2020" :)

1 0

Re: Printer - RBB or CMYK?
by David Wollmann 08 Jan '20

08 Jan '20

In my experience most Laser printers expect to receive RGB data. It’s easy to print a standard test target in RGB and CMYK and evaluate the results, usually the RGB shows smoother prints with better gamut. Sending a black target as you describe is full of things to trip over while trying to maintain a single color black. If sending from Adobe products such as InDesign or Illustrator what are your Appearance of Black Preferences set to? Does it treat all blacks accurately or does it send Rich blacks out? If creating a PDF how are you managing blacks and color conversions, is the pdf even tagged? Many factors can alter your single color blacks before it gets to the printer. Check with the manufacturer, often it can be found on a web site. David Wollmann > On Jan 8, 2020, at 3:47 PM, colorsync-users-request(a)lists.apple.com wrote: > > From: PPS Lists <lists(a)precisionpixelstudios.com <mailto:lists@precisionpixelstudios.com>> > > I used to know how to do this but it has been so long since I have needed to I have forgotten how. > > I need to determine if the print pipeline for a certain laser printer is RGB or CMYK. I used to know how to spin up a Photoshop file in a certain way and send to print. > > IIRC, the procedure was along the lines of make a CMYK document, and create a black square of equal parts of Cyan, Magenta and Yellow. Then slap a smaller 100% black square on top of the CMY square and send to print. Something like that. > > Does anyone know the correct steps? > > Thank you.

1 0

Re: 1 billion colors
by Wire ~ 08 Jan '20

08 Jan '20

Ah ok, I follow you. Ya, I found another ref to the same thing for this model. FRC is new to me. Thx. I'm trying to get mine into 10-bit mode. All the parts—OS, graphics card and display, should be able to do it, but no luck. For any Mac users, I've got an old 2008 Mac Pro which I am keeping up to date with DosDude1's fantastic Mojave Patcher that allows late-version MacOS on systems Apple no longer supports. This hasn't been treacherous at all, but it adds more variables to an already complicated environment. On Wed, Jan 8, 2020 at 2:40 PM <graxx(a)videotron.ca> wrote: > Sorry! AFC -- yes, "Frame Rate Control" - "FRC" -- my bad! > > Apparently, your Dell uses that, according to the web site link you gave > me? Just as my NEC does? Only Andrew's NEC PA271Q (more recent panel) has a > "true" 10-bit panel. >

1 1

Re: 1 billion colors
by Wire ~ 08 Jan '20

08 Jan '20

Re AFC, do you mean FRC (frame rate control)? 'm not up to speed on this tech. I can't say if this Dell uses it, but I would think not because IPS is pretty slow and the wikis say FRC is a TN (faster) panel tech. On Wed, Jan 8, 2020 at 2:18 PM <graxx(a)videotron.ca> wrote: > Wire, > > > > Here's the "trend" I was looking for. I don't have the time to put all > these separate Excel sheets into one (for now) but if you look closely at > the graphs in each document, you will see the "trend" I'm talking about. > > > > What my instrument captured is the fact that, there is no "loss" in the > shadows, going from finer and finer RGB increments, from 0 to 65536 code > values (equivalent to 16-bit Photoshop color mode), but there is a visible > progressive loss in the highlights (staircase pattern). And I'm pretty sure > this is independent of monitor Luminance such that, if I was (and I will) > to redo these measurements at say, 120 cd/m2 or 160 (as opposed to my > current, lowly 60 cd/m2), the relationship between inputs and outputs would > not change, it would be the same pattern albeit scaled differently. > > > > Someone could unequivocally conclude from this data, Wire, that, in a > 10-bit video environment (which is the case of my NVIDIA video card and > (crappy?) NEC PA271W monitor capabilities (remember this model uses > 8bit+AFR for an 'effective' 10-bit experience, same as your Dell, which > some argue can't be distinguished from true 10-bit panel), detail is > *preserved* in the shadows at the expense of the highlights. > > > > You see where I'm going? More to follow 😊 > > > > / Roger >

1 0

RE: Humans (and cameras and scanners) do not have a color gamut (?)
by graxx＠videotron.ca 08 Jan '20

08 Jan '20

The "Jack Holm" from HP? / Roger -----Original Message----- From: colorsync-users <colorsync-users-bounces+graxx=videotron.ca(a)lists.apple.com> On Behalf Of Iliah Borg via colorsync-users Sent: Wednesday, January 8, 2020 4:36 PM To: Wayne Bretl <waynebretl(a)cox.net> Cc: 'Andrew Rodney via colorsync-users' <colorsync-users(a)lists.apple.com> Subject: Re: Humans (and cameras and scanners) do not have a color gamut (?) > See Jack Holm's paper ... where he derives the spectral locus of a > combination of a sensor's outputs and a subsequent matrix I've read that paper when it was first published on the web ;) It doesn't define sensor gamut, or gamut of sensor outputs. To quote, "This paper reports on the observed characteristics of the capture color analysis gamuts resulting from a number of capture devices/media, and scene analysis color matrices." The result depends on the matrix. Strongly depends, as the paper itself demonstrates. That matrix defines the relation between the camera observer and colorimetric observer. On Jan 8, 2020, at 4:21 PM, Wayne Bretl via colorsync-users wrote: > Arrgh - addressing problems - went only to iliah and not the whole > list as intended > > -----Original Message----- > From: Wayne Bretl <waynebretl(a)cox.net> > Sent: Wednesday, January 08, 2020 2:13 PM > To: 'Iliah Borg' <iliah.i.borg(a)gmail.com> > Subject: RE: Humans (and cameras and scanners) do not have a color > gamut (?) > > See Jack Holm's paper, which I posted above, where he derives the > spectral locus of a combination of a sensor's outputs and a subsequent matrix: > http://www.color.org/documents/CaptureColorAnalysisGamuts.pdf > > Although he does not show the sensor outputs themselves, they have > reached their extreme possible ratios when the stimulus is a single > wavelength, and therefore a pseudo chromaticity chart could be plotted > using the ratios of one channel to the sum of the three on one axis > and a ratio of a second channel to the sum on the orthogonal axis. > This chart would have a defined gamut of sensor values (inside the > spectrum locus) but would not represent colors per se until processed through a matrix. > > Holm shows the resulting chromaticities for multiple sensors and > several reasonable matrices. He includes cases for motion picture > negative film that clearly show a triangular gamut limit (spectral locus). > > -----Original Message----- > From: Iliah Borg <iliah.i.borg(a)gmail.com> > Sent: Wednesday, January 08, 2020 1:59 PM > To: Wayne Bretl <waynebretl(a)cox.net> > Cc: Andrew Rodney <andrew(a)digitaldog.net>; Andrew Rodney via > colorsync-users <colorsync-users(a)lists.apple.com> > Subject: Re: Humans (and cameras and scanners) do not have a color > gamut (?) > > > On Jan 8, 2020, at 3:52 PM, Wayne Bretl via colorsync-users wrote: >> . >> The discussion has moved beyond the true but uninformative statement >> that cameras (sensors to be precise) do not have a color gamut , to >> considering how the gamut of sensor outputs > > I would very much like a definition here. What is the gamut of sensor > outputs? > > And of course, how to measure it? > > -- > Best regards, > Iliah Borg > LibRaw, LLC > www.libraw.org > www.rawdigger.com > www.fastrawviewer.com > > > > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > colorsync-users mailing list (colorsync-users(a)lists.apple.com) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/colorsync-users/iliah.i.borg%4 > 0gmail.com > > This email sent to iliah.i.borg(a)gmail.com -- Best regards, Iliah Borg LibRaw, LLC www.libraw.org www.rawdigger.com www.fastrawviewer.com _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx(a)videotron.ca

2 1

Re: 1 billion colors
by Wire ~ 08 Jan '20

08 Jan '20

Sry for being dense, do you mean: Of all the colors your display produces, how many of them can be considered perceptually distinct? From a sort of holistic perspective, like if you took a 17 million color RGB test chart under Adobe RGB, and grouped similar pixels to form lumps of similarity, how many lumps would there be and what would their distribution look like? I need help with your charts... Can you give a quick rundown? On Wed, Jan 8, 2020 at 1:45 PM <graxx(a)videotron.ca> wrote: > Wire, > > > Ask why you want an answer to this question... and if you don't know > exactly why you might > > abandon it for now and see where it pops up again. > > The only reason I am investigating this is to be able to tell just to what > extent the difference can actually be seen. > > Take a look at the data I've cranked since this morning, working on my > application. > > There are lots of questions I'm trying to answer. I'm aware of the > decisions I made so far and their possible effects on the measurements like > the fact that I'm running my monitor at such a low Luminance level... > > Before going any further with gathering more data, I'll take a few moments > to chew on what I already gathered and see whether I can spot a trend... > > / Roger >

1 0

RE: Humans (and cameras and scanners) do not have a color gamut (?)
by graxx＠videotron.ca 08 Jan '20

08 Jan '20

Karl is good 😊 / Roger -----Original Message----- From: colorsync-users <colorsync-users-bounces+graxx=videotron.ca(a)lists.apple.com> On Behalf Of Andrew Rodney via colorsync-users Sent: Wednesday, January 8, 2020 3:34 PM To: 'colorsync-users?lists.apple.com' List <colorsync-users(a)lists.apple.com> Subject: Re: Humans (and cameras and scanners) do not have a color gamut (?) On Jan 8, 2020, at 12:41 PM, Wire ~ via colorsync-users <colorsync-users(a)lists.apple.com> wrote: > > So what's the proper definition of the term gamut: Karl Lang, the established Colour Scientist explains exactly what Colour Gamut is. Watch, pay attention, learn: https://www.youtube.com/watch?v=W--le887BvM <https://www.youtube.com/watch?v=W--le887BvM> _______________________________________________ Do not post admin requests to the list. They will be ignored. colorsync-users mailing list (colorsync-users(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/colorsync-users/graxx%40videotron.ca This email sent to graxx(a)videotron.ca

1 0

RE: Humans (and cameras and scanners) do not have a color gamut (?)
by Wayne Bretl 08 Jan '20

08 Jan '20

Thank you. I love it when people are in violent agreement, but prefer a greater emphasis on agreement and less on violence. ;>) From: Andrew Rodney <andrew(a)digitaldog.net> Sent: Wednesday, January 08, 2020 2:02 PM To: Wayne Bretl <waynebretl(a)cox.net> Subject: Re: Humans (and cameras and scanners) do not have a color gamut (?) On Jan 8, 2020, at 1:52 PM, Wayne Bretl <waynebretl(a)cox.net <mailto:waynebretl@cox.net> > wrote: Sorry, this video talks about the gamut of displays, but not about cameras and whether they have a gamut or not. Yes, it was in response to Wire's question about "what is gamut" (and i pointed out we're talking color gamut). Karl isn't going to state digital camera have a color gamut either. Simply repeating that "cameras do not have a color gamut" is not furthering this discussion. Please stop. No need to continue posting what Fairchild, his entire facility and Parker have stated. I agree. By definition, the raw outputs of a sensor are not colors and therefore do not represent a color gamut. Fine. I agree. That only goes to that stage of the process and offers no insight into how the sensor responses affect the gamut of the colors derived from the sensor outputs. I agree. A rendered image absolutely has a color gamut. The discussion has moved beyond the true but uninformative statement that cameras (sensors to be precise) do not have a color gamut , to considering how the gamut of sensor outputs may restrict the gamut of reported colors when converted to a color space. I didn't believe that was ever disputed nor should it be. I made a previous comment about scanners, and the resulting color gamut from a profile and I equally believe we can examine the color gamut of a scanned image in something like ColorThink Pro. I've done this often. If anyone here is suggesting the results from a digital camera (a rendered image in a RGB color space) or a scanner has no color gamut, I missed that and I don't agree. I would add the further note that sometimes the sensor gamut is the limiting factor on the final color output, and sometimes the color space (e.g. sRGB) is the limiting factor. Absolutely agree. Andrew Rodney http://www.digitaldog.net/

1 0