March 2015 - colorsync-users

Pantone RGB/CMYK values
by Mark Franzen 31 Mar '15

31 Mar '15

Hello - I am sure this question has been asked before, but I need to ask it again anyway. I am wondering about the RGB and CMYK values that are give by Pantone in their “Color Bridge” book and elsewhere. It has the Solid swatch and a CMYK process swatch. Under those swatches are RGB and CMYK values. I fully understand the differences between the solid and process colors, but I am a little unclear as to WHICH RGB and CMYK those numbers are referring. Why would those numbers not be given in L*a*b? I did see in the first few pages of the Pantone book that sRGB was referenced, and I am assuming that when Pantone gives RGB numbers, at least in the book that I am referencing, that those numbers relate to sRGB - maybe I am answering my own question there. I did also read that the CMYK “screen tint” percentages were given. How do those numbers relate to a CMYK file that I could use in Photoshop? If I create a new Photoshop file in sRGB, Adobe RGB (1998), and ColorMatch and fill each those with the numbers called out, I get three images with very different color appearances. I also did the same thing with three different CMYK files. I was using Pantone Red 032C for my test. RGB values in the book were R-237 G-41 B-57. I also understand that each RGB and CMYK is going to have their own gamut and “flavor”, but my question is, which one is right? Thanks for the help. Mark Franzen mfranzen3(a)wi.rr.com

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Re: Pantone RGB/CMYK values
by Thomas Richard 31 Mar '15

31 Mar '15

Hello Mark, as far as I remember, these CMYK-values base on the PANTONE PROCESS colors on the first page of the Colorbook. PANTONE Process Yellow CP PANTONE Process Magenta CP PANTONE Process Cyan CP PANTONE Process Black CP Measuring those patches, you will get densities about 2.0 So there is almost no chance to meet those colorimpressions in a normal CMYK Workflow. MfG Thomas >Hello - > >I am sure this question has been asked before, but I need to ask it again anyway. > >I am wondering about the RGB and CMYK values that are give by Pantone in their "Color Bridge" book and elsewhere. It has the Solid swatch and a CMYK process swatch. Under those swatches are RGB and CMYK values. I fully understand the differences between the solid and process colors, but I am a little unclear as to WHICH RGB and CMYK those numbers are referring. Why would those numbers not be given in L*a*b? > >I did see in the first few pages of the Pantone book that sRGB was referenced, and I am assuming that when Pantone gives RGB numbers, at least in the book that I am referencing, that those numbers relate to sRGB - maybe I am answering my own question there. > >I did also read that the CMYK "screen tint" percentages were given. How do those numbers relate to a CMYK file that I could use in Photoshop? > >If I create a new Photoshop file in sRGB, Adobe RGB (1998), and ColorMatch and fill each those with the numbers called out, I get three images with very different color appearances. I also did the same thing with three different CMYK files. I was using Pantone Red 032C for my test. RGB values in the book were R-237 G-41 B-57. I also understand that each RGB and CMYK is going to have their own gamut and "flavor", but my question is, which one is right? > > >Thanks for the help. > >Mark Franzen >mfranzen3(a)wi.rr.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/tr%40e-b-v.de > >This email sent to tr(a)e-b-v.de

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wide screen display
by Remington, David 25 Mar '15

25 Mar '15

Hello, We are looking to replace our conference room "monitor". We use this display to review work as a group within our department and to go over examples with curatorial and collection management staff. Plus look at notes, spreadsheets, general project planning, visiting colleges will hook it up to their laptops to share work, etc... I purchased a 46 inch NEC P461 about 5 years ago. It's OK straight on but off axis is not so great. The key for me was that it is supported by Spectraview and can be easily calibrated. We would like to bump up the size a bit to 55 or 60 inches. 1920x1080 is fine. Does any one know of a good quality, preferably IPS, screen in this size? Hardware calibration a big plus. NEC makes some new screens now but all are SPVA as is our current screen. LG makes IPS "TV's" in 55 inch and larger sizes. Most are 4K though and I'm skeptical of how well one work work for image review. Thanks in advance for any tips. —David David Remington Manager, Digital Imaging and Photography Services Harvard Library Preservation D-70A Widener Library Cambridge, MA 02138 p 617-495-4701 f 617-495-0403 w http://imaging.harvard.edu/

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i1profiler -- Could not compute white point from measurement conditions M1 (D50)
by Roger Breton 25 Mar '15

25 Mar '15

I'm curious about the meaning of this message which is presented to the user at the time of loading a CGATS21 dataset into the Measure section of i1Profiler, for the purpose of creating an output profile. Curious because Lines 6 and 7 of the CGATS file in question specifically state : > MEASUREMENT_GEOMETRY "ISO 13655 - Reflection, M1, white backing" > FILTER "D50" Why would i1Profiler "need" to compute a white point at all? The very first line of the data section reads : > 1 0 0 0 0 95 1 -4 Which defines 0c 0m 0y 0k *as* Lab 95 1 -4. I feel like ignoring the message altogether but there was this other message that appeared when I loaded the dataset with regards to "Calibration"? I was given the choice between : a) XRGA b) GMDI c) XRDI d) NIST e) Legacy standard Any help is appreciated, Roger Breton

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The G7 method
by Roger Breton 11 Mar '15

11 Mar '15

I need to ask a favor. I'm struggling with the fangraph method. Maybe just silly again? Figuring the K fangraph is straightforward, but not the CMY. I'm in the 2009 G7 How-to (http://www.idealliance.org/downloads/g7-how-2009-g7-manual) In "3.4 Measuring the P2P Target", the instructions state: > Measure the ND (Neutral Density) values of the K-only gray scale (P2P column 4) and the CMY only > gray scale (P2P column 5) Is "Neutral Density" the same as ISO (Status T) Visual density? Is seems that way since the next paragraph reads : > The target can be measured with spot readings using a hand-held densitometer set to the Black, or Visual channel So, to me, that much should be clear. Well, on page 12, "3.5 Plotting the Common CMY NPDC Curve", in Figure 3.8, the ND values are listed under the Cyan column. Is this correct? I assume it is. Where I seem to get confused is in the next sentence which reads : > ... Use blue ink as the initial CMY sample graph becomes the cyan graph when correcting gray balance. In other words, the "ND" values, which are also ISO Visual (?) are to be treated as "Cyan" density values? For the purpose of drawing the graph? In other words, is the initial press curve to be drawn based on ISO (Status T) Visual densities? Best / Roger P.S. I'm doing this manually for my students as an exercice in press calibration using the G7 method (I know there is always IDEALinkCurve...).

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Re: How to use i1Profiler to measure a P2P25 target
by William Whitfield 11 Mar '15

11 Mar '15

Greetings Steve, Thank you for the additional information about the P2P target. A check of my reference files shows that the values match those of the distributed P2P reference files. I have been aware of those xx.xx values in the P2P reference and have wondered if it really makes a difference between the printed results of 4.71% and the printed results of a 5% when determining gray balance curve points, at least in the flexo world that I live in. -Bill-

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RE: How to use i1Profiler to measure a P2P25 target
by William Whitfield 10 Mar '15

10 Mar '15

Greetings Roger, I also had challenges, so I built my own P2P tif and reference file, one for the iO and one for the iSis. They are formatted to look just like the”supplied" P2P targets with the same number of rows and columns. It seems that iProfiler gets confused with some text files in terms of formatting the chart in iProfiler to match the actually printed chart. Sometimes playing with the page size fixes this and sometimes it does not. So I just made my own. You are welcome to the files for future use. -Bill- On Mar 9, 2015, at 12:00 PM, colorsync-users-request(a)lists.apple.com wrote: > Send Colorsync-users mailing list submissions to > colorsync-users(a)lists.apple.com > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.apple.com/mailman/listinfo/colorsync-users > or, via email, send a message with subject or body 'help' to > colorsync-users-request(a)lists.apple.com > > You can reach the person managing the list at > colorsync-users-owner(a)lists.apple.com > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Colorsync-users digest..." > > > Today's Topics: > > 1. How to use i1Profiler to measure a P2P25 target (Roger Breton) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 08 Mar 2015 23:24:22 -0400 > From: Roger Breton <graxx(a)videotron.ca> > To: "''colorsync-users?lists.apple.com' List'" > <colorsync-users(a)lists.apple.com> > Subject: How to use i1Profiler to measure a P2P25 target > Message-ID: <008101d05a18$897a8f50$9c6fadf0$(a)videotron.ca> > Content-Type: text/plain; CHARSET=US-ASCII > > I am probably wasting my time but I need to ask, in case, is there any way > to read a "Standard" P2P25Xa target with and i1Pro in i1Profiler? > > I've tried many things to no avail :( > > > > Best / Roger > > > > ------------------------------ > > _______________________________________________ > Colorsync-users mailing list > Colorsync-users(a)lists.apple.com > https://lists.apple.com/mailman/listinfo/colorsync-users > > End of Colorsync-users Digest, Vol 12, Issue 41 > *********************************************** >

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Re: How to use i1Profiler to measure a P2P25 target
by William Whitfield 10 Mar '15

10 Mar '15

Greetings Roger, I stand corrected, and educated. I have been using the profiling workflow of iProfiler to measure all my charts. When I follow the instructions given with the P2P25Xa chart and use the measure reference chart workflow in iProfiler, I am able to measure the P2P25Xa. I know amazing that a man would read instructions, which I found on the IDEAlliance website after submitting my previous comments. Well, I stand accused. Interesting though, when I try to use the measure chart workflow, iProfile will not see my iSis, however when I use the aforementioned measure reference workflow it will see my iSis. By the way please do not tell my wife I read instructions - that would set up all kinds of challenges in the future :-) -Bill- On Mar 9, 2015, at 12:00 PM, colorsync-users-request(a)lists.apple.com wrote: > Send Colorsync-users mailing list submissions to > colorsync-users(a)lists.apple.com > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.apple.com/mailman/listinfo/colorsync-users > or, via email, send a message with subject or body 'help' to > colorsync-users-request(a)lists.apple.com > > You can reach the person managing the list at > colorsync-users-owner(a)lists.apple.com > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Colorsync-users digest..." > > > Today's Topics: > > 1. How to use i1Profiler to measure a P2P25 target (Roger Breton) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 08 Mar 2015 23:24:22 -0400 > From: Roger Breton <graxx(a)videotron.ca> > To: "''colorsync-users?lists.apple.com' List'" > <colorsync-users(a)lists.apple.com> > Subject: How to use i1Profiler to measure a P2P25 target > Message-ID: <008101d05a18$897a8f50$9c6fadf0$(a)videotron.ca> > Content-Type: text/plain; CHARSET=US-ASCII > > I am probably wasting my time but I need to ask, in case, is there any way > to read a "Standard" P2P25Xa target with and i1Pro in i1Profiler? > > I've tried many things to no avail :( > > > > Best / Roger > > > > ------------------------------ > > _______________________________________________ > Colorsync-users mailing list > Colorsync-users(a)lists.apple.com > https://lists.apple.com/mailman/listinfo/colorsync-users > > End of Colorsync-users Digest, Vol 12, Issue 41 > *********************************************** >

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Re: P2P in i1 Profiler
by Glenncolorguy 10 Mar '15

10 Mar '15

....So glad to hear I'm not the only one. > > I am probably wasting my time but I need to ask, in case, is there any way > to read a "Standard" P2P25Xa target with and i1Pro in i1Profiler? > > I've tried many things to no avail :( > > > > Best / Roger > > > > ------------------------------ > > _______________________________________________ > Colorsync-users mailing list > Colorsync-users(a)lists.apple.com > https://lists.apple.com/mailman/listinfo/colorsync-users > > End of Colorsync-users Digest, Vol 12, Issue 41 > ***********************************************

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Re: How to use i1Profiler to measure a P2P25 target
by Bret Hesler 10 Mar '15

10 Mar '15

It has been a while since I set it up, but I imported it into (or it was already there) the measure reference chart workflow. I can email you the workflow I have for the i1Pro2. Bret Subject: How to use i1Profiler to measure a P2P25 target > Message-ID: <008101d05a18$897a8f50$9c6fadf0$(a)videotron.ca> > Content-Type: text/plain; CHARSET=US-ASCII > > I am probably wasting my time but I need to ask, in case, is there any way > to read a "Standard" P2P25Xa target with and i1Pro in i1Profiler? > > I've tried many things to no avail :( > > > > Best / Roger > > >

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