June 2013 - colorsync-users

Re: Colorimetric Accuracy in the Field
by Henry Davis 17 Jun '13

17 Jun '13

Andrew - When I wrote "you have used dE as both a sword and a shield," I figured that readers would understand the inference was that dE is a method for determining a colorimetric match - that dE is pretty much colorimetry itself. As an expert in profiling and color management you've insisted that colorimetric matches aren't the purpose of profiling or a color managed workflow. Yet you, and others, offer dE as a measure of the quality of a profile or workflow. Thus, colorimetric matches play an important part in evaluating your work - no? It's a good thing when it promotes the case for profiling and its shortcomings are also a good thing as that promotes the need for skilled professionals at the helm - sword and shield. You understand the confusion this must cause - I believe that's what you mean by the "rabbit hole". But I don't believe I've heard you give a satisfactory answer in this thread as to why colorimetric matching is and isn't important - all at the same time. You've only offered that it's not important to a majority of photographers. It must be too difficult for people to understand so we have to settle for it as the rabbit hole instead. That saves time and possibly even more confusion. It protects the colorimetric grail searchers from themselves? You've asked, in a challenging way, for a definition of "colorimetric" from participants in this thread so I figure you're quite ready to spring on any definition with answers that would belittle the pursuit of colorimetric matching. Do you have a definition that's better than the deficient ones in use? I think that might clear up some of the confusion. May I say that this topic might be interesting to more people than you think, and with your professional experience I bet you can lay it all out in a clear way so that this rabbit hole isn't so dark and mysterious. This topic has appeared in the colorsync-users list a number of times and this time it seems that the subject of RPP along with some ideas from members has brought it back with a little more enthusiasm. Henry

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Request for Color Managed workflow solutions/ideas
by Frederick Park 15 Jun '13

15 Jun '13

Friends / Readers @ Colorsync User Group, Recently lost my shop. Looking to start over. (I've been reading this list for almost 10 years.) Want to ask for ideas (shop / studio of professional photographer, designer with high-end print capabilities) from the pros and those with their hands deep in color management. Have: Mac Book Pro (2009) Epson 7600 (thinking of "upgrading" to latest model) Canon D1 Solux Booth Lights (both D65 and D50) Need: Scanner (for reflective and transmissive scans) Colorimeter/Spectrophotometer/Profiling - hardware/software (want recommendations on XRite's best package - they will not honor my stollen dongle, have to "start over" with them) RIP - this is a big question for "best solution" for new Epson 7600! (had Best Color) New Insurance options . . . Since my Color Management expertise is about all I stand upon presently, I'm open to any and all suggestions for rebuilding my workflow. If any of you could make a "start-to-finish" or "input - managed workflow - output" wish list, here is an option to share that either in this list or with me via email. Thank you all, in advance, for any ideas you're willing to share. Frederick Park Asheville, NC 828.335.5630 - cell frederick(a)apalache.com

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Re: Thank you X-Rite!
by John Vitollo 13 Jun '13

13 Jun '13

I'm sure with a Lego Mindstorms kit my 15 year-old nephew could build a automated target reader!

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Re: Thank you X-Rite!
by John Lund 13 Jun '13

13 Jun '13

Hello folks, Hmm, I do remember the Spectralvision Pro iteration of ColorPort at least read linearization charts (hey, remember those?) in either direction. But maybe that was just when using the DTP20 Pulse? One thing ColorPort & Spectralvision Pro did that made for a MUCH better user experience on the iO table, was that to first set the 3 corner patches, you could "click" using the mouse, not just the button on the i1Pro. That seems to have gotten lost on i1Profiler. Using the button on my i1Pro (original) frequently results in the software detecting 2 clicks instead of one, moving past the corner patch I'm trying to mark to the next one. No way to correct this, just have to complete this step, then hit "start over". At first I thought it might just be a "hair trigger" button, but it seems to be a random result. Makes me long for those old days when I could position the i1Pro, then just click the mouse to set patch position. Anybody else see this on an i1 iO table? John JWL Images Emeryville, CA On Jun 12, 2013, at 8:31 AM, colorsync-users-request(a)lists.apple.com wrote: > Message: 6 > Date: Wed, 12 Jun 2013 10:29:16 -0400 > From: Terence Wyse <wyseconsul(a)mac.com> > To: "colorsync-users(a)lists.apple.com List" > <colorsync-users(a)lists.apple.com> > Subject: Re: Thank you X-Rite! > Message-ID: <02C864BE-6972-4891-A856-0FE8059770AD(a)mac.com> > Content-Type: text/plain; charset=us-ascii > > ColorPort never had bi-directional charts for the i1Pro....still doesn't AFAIK. > > Terry

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Thank you X-Rite!
by Peter Miles 12 Jun '13

12 Jun '13

Today I've been reading profile patches in i1Profiler by hand, using the i1pro and newer version of the 'scan ruler'. Seven profiles with 3000 patch charts for each. Half way through reading the fifth set of patches I got so annoyed at how slow all this hand scanning was going that I deliberately read the next strip of patches in the WRONG direction! "Take that!" I thought. To my utter delight i1Profiler took it in it's stride and put the measurements in the right way around. Taking advantage this newly discovered ability of i1Profiler's ability to read patch strips in either direction speed things up from there. I realised that as an old spectral vision pro (colorburst) user, I had been habituated to having to scan patches in the 'right direction'. I had unthinkingly carried this habit over to using i1Profiler. Thanks XRite for that feature! Regards Peter Miles

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thank you x-rite
by Spinnaker Photo Imaging Center 12 Jun '13

12 Jun '13

What version of 1Pro are you using? David On Jun 12, 2013, 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. Re: Thank you X-Rite! (John Lund) > 2. Re: Thank you X-Rite! (Terence Wyse) > 3. Re: Thank you X-Rite! (dpascale) > 4. Re: Thank you X-Rite! (dpascale) > > > > From: John Lund <john(a)jwlimages.com> > Date: June 12, 2013 9:02:06 AM PDT > To: colorsync-users(a)lists.apple.com > Subject: Re: Thank you X-Rite! > > > Hello folks, > > Hmm, I do remember the Spectralvision Pro iteration of ColorPort at least read linearization charts (hey, remember those?) in either direction. But maybe that was just when using the DTP20 Pulse? > > One thing ColorPort & Spectralvision Pro did that made for a MUCH better user experience on the iO table, was that to first set the 3 corner patches, you could "click" using the mouse, not just the button on the i1Pro. That seems to have gotten lost on i1Profiler. > > Using the button on my i1Pro (original) frequently results in the software detecting 2 clicks instead of one, moving past the corner patch I'm trying to mark to the next one. No way to correct this, just have to complete this step, then hit "start over". At first I thought it might just be a "hair trigger" button, but it seems to be a random result. Makes me long for those old days when I could position the i1Pro, then just click the mouse to set patch position. > > Anybody else see this on an i1 iO table? > > John > JWL Images > Emeryville, CA > > > On Jun 12, 2013, at 8:31 AM, colorsync-users-request(a)lists.apple.com wrote: > >> Message: 6 >> Date: Wed, 12 Jun 2013 10:29:16 -0400 >> From: Terence Wyse <wyseconsul(a)mac.com> >> To: "colorsync-users(a)lists.apple.com List" >> <colorsync-users(a)lists.apple.com> >> Subject: Re: Thank you X-Rite! >> Message-ID: <02C864BE-6972-4891-A856-0FE8059770AD(a)mac.com> >> Content-Type: text/plain; charset=us-ascii >> >> ColorPort never had bi-directional charts for the i1Pro....still doesn't AFAIK. >> >> Terry > > > > > > > > > > From: Terence Wyse <wyseconsul(a)mac.com> > Date: June 12, 2013 9:12:01 AM PDT > To: John Lund <john(a)jwlimages.com>, "'colorsync-users?lists.apple.com' List" <colorsync-users(a)lists.apple.com> > Subject: Re: Thank you X-Rite! > > > > On Jun 12, 2013, at 12:02 PM, John Lund <john(a)jwlimages.com> wrote: > >> Hmm, I do remember the Spectralvision Pro iteration of ColorPort at least read linearization charts (hey, remember those?) in either direction. But maybe that was just when using the DTP20 Pulse? > > The Pulse could definitely read bi-directional....and measure rows out of order for that matter in ColorPort. The Pulse charts used a row identifier that took care of all this.....the i1Pro, not so much. > > Only problem with the Pulse was the reliance on a chart target identifier that relied on color codes......on a "raw" print from an inkjet printer, many times the 100% green patches were indistinguishable from black and would cause it to wig out. > > Terry > > > > > > > > > > > From: dpascale <dpascale(a)babelcolor.com> > Date: June 12, 2013 10:43:55 AM PDT > To: Andrew Rodney <andrew(a)digitaldog.net>, colorsync-users(a)lists.apple.com > Subject: Re: Thank you X-Rite! > > > "> Moving in dual directions (left to right or right to left) was something the original i1Pro did as well. Nothing new here. " > > Yes indeed. But with the i1Pro 2 + new ruler, bidirectional scan is also possible when target measurements are done without using a file with reference data, such as RGB or CMYK. We just need to specify the number of columns. > > Danny Pascale > > www.babelcolor.com > > > ----- Original Message ----- From: "Andrew Rodney" <andrew(a)digitaldog.net> > To: <colorsync-users(a)lists.apple.com> > Sent: Wednesday, June 12, 2013 10:03 AM > Subject: Re: Thank you X-Rite! > > >> On Jun 12, 2013, at 12:50 AM, Peter Miles wrote: >>>> Half way through reading the fifth set of patches I got so annoyed at how slow all this hand scanning was going that I deliberately read the next strip of patches in the WRONG direction! "Take that!" I thought. To my utter delight i1Profiler took it in it's stride and put the measurements in the right way around. Taking advantage this newly discovered ability of i1Profiler's ability to read patch strips in either direction speed things up from there. >> >> Moving in dual directions (left to right or right to left) was something the original i1Pro did as well. Nothing new here. >> >> Andrew Rodney >> http://www.digitaldog.net/ >> _______________________________________________ > > > > > > > > > > From: dpascale <dpascale(a)babelcolor.com> > Date: June 12, 2013 10:55:09 AM PDT > To: Lee Badham <lee.b(a)bodoni.co.uk>, Michael Eddington <meddington38(a)gmail.com> > Cc: colorsync-users(a)lists.apple.com > Subject: Re: Thank you X-Rite! > > > Hello Lee, > > "> The i1 just reports a list of patches. It is up to the software to decide which way the strip was read in." > > It can be either way. > > The i1Pro 2 can automatically provide data in the proper order if configured for it by the program, either by using a predefined color lists or by using the new ruler input. > > Data can also be ordered in the software, but that requires either a predefined color list or a "start/end of line" marker (bar code). > > Danny Pascale > > www.babelcolor.com > > > > ----- Original Message ----- From: "Lee Badham" <lee.b(a)bodoni.co.uk> > To: "Michael Eddington" <meddington38(a)gmail.com> > Sent: Wednesday, June 12, 2013 10:22 AM > Subject: Re: Thank you X-Rite! > > >> Hi, >> >> The i1 just reports a list of patches. It is up to the software to decide which way the strip was read in. >> >> Lee >> >> On 12 Jun 2013, at 15:15, Michael Eddington wrote: >> >>> Was the ability to read in either direction tied to the reference >>> file? Seem to me that capability came and went when measuring strips >>> of different origins. >>> >>> Mike >>> >>> >>> On Jun 12, 2013, at 10:05 AM, Andrew Rodney <andrew(a)digitaldog.net> wrote: >>> >>>> On Jun 12, 2013, at 12:50 AM, Peter Miles wrote: >>>>>> Half way through reading the fifth set of patches I got so annoyed at how slow all this hand scanning was going that I deliberately read the next strip of patches in the WRONG direction! "Take that!" I thought. To my utter delight i1Profiler took it in it's stride and put the measurements in the right way around. Taking advantage this newly discovered ability of i1Profiler's ability to read patch strips in either direction speed things up from there. >>>> >>>> Moving in dual directions (left to right or right to left) was something the original i1Pro did as well. Nothing new here. >>>> >>>> Andrew Rodney >>>> http://www.digitaldog.net/ >>>> _______________________________________________ > > > > > > > _______________________________________________ > Colorsync-users mailing list > Colorsync-users(a)lists.apple.com > https://lists.apple.com/mailman/listinfo/colorsync-users

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Re: Colorimetric Accuracy in the Field
by Bruce J. Lindbloom 10 Jun '13

10 Jun '13

David B Miller, Pharm. D. wrote: >Repeating, I am just delighted to be in the wabbit whole. But it's such a wascally wabbit! -- Bruce J. Lindbloom bruce(a)brucelindbloom.com http://www.brucelindbloom.com

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Re: Colorimetric Accuracy in the Field
by Henry Davis 09 Jun '13

09 Jun '13

Andrew wrote: " . . . And measuring two samples of say output of a printer with a Spectrophotometer is a quite different from measuring a sample at the scene (which isn't what one proponent of colorimetrically accurate raw processing has done), since the illuminant in the measuring device is often quite different from the illuminate of the scene! You think that plays a role?" Henry: I suspect that camera manufacturers might disagree with you here in that they are probably very keen on understanding the response of their camera system as it records a scene. > As an expert in profiling and color management you've insisted that > colorimetric matches aren't the purpose of profiling or a color > managed workflow. Andrew Replied: I've never said that. Or you completely misunderstood what I've said. Henry replies: I recall that you made that assertion in a thread regarding the failure of ICC profiles to produce matches to Pantone colors that are within a printer's gamut. It may have been someone else but I think it was you. I believe you went on to say or imply that it wasn't ever the intent or goal for ICC profiles. Pursuing the question in threads like this seems to always lead to more rabbit hole reasons for dismissing the idea of Colorimetric matching. Maybe I do misunderstand but I can't get through the confusion without some clarification, and maybe I'm not the only one who's confused. > Thus, colorimetric matches play an important part in evaluating your > work - no? Andrew Replied: . . . In the example above indeed! This is vastly different from saying a process is colorimetrically accurate without a 2nd set of measurements Henry replies: It sounds as though you are defining colorimetric accuracy based on close agreement in measurements. I'll go with that - up to a point. I don't know a better way to define it with consistency. Have you experienced a measured colorimetric accuracy of two samples that failed to be visually accurate? If colorimetric accuracy is so important on the one hand then why is it that on the other hand you dismiss the pursuit of it as too difficult or too complex? Nobody is suggesting that this is a simple task. Nobody is saying that the illuminant isn't a hugely important factor. Nobody is saying that a majority of photographers have an interest in this - at least for now. You conclude that it's not complex if people just accept what some people say. ? ? ? You say that people don't even understand how to ask the proper questions. ? ? ? I'm not exactly sure what the message is you're trying to communicate with all of that but it doesn't sound very nice. It makes me want to apologize for testing your patience. I get it, I get it, I get it: measuring two patches isn't the same as shooting in the field. But I think you would have to admit that there is a starting point for the camera in the field and that the manufacturer probably took a few measurements and did some research involving colorimetric matching. It would be very interesting to find that their R&D starting point was pleasing color instead of colorimetric. That would be a worse rabbit hole, don't you think? Henry

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Colorimetric Accuracy In the Field
by Jeffrey Stevensen 09 Jun '13

09 Jun '13

One more issue that rears it's head regarding the quest for colorimetric accuracy in the field is the multiplicity of light sources encountered. Taking a sunny day landscape or architecture shot, we have the sun and then the open sky. Just as importantly, we then have the multiplicity of environmental reflections coming in all directions. If you meter the sunlight, what happens to your accuracy as more or less of these lights mix in different parts of the scene? It's my experience that color temperature will vary over as little as a couple feet or even the angle of the metering instrument to the light sources, or the angle of the target to the main light (the sun) and the mix of other reflections, or the color of a wall or pavement or greenery and trees. It seems to me that the colorimetric accuracy would come down to only a very specific white balance in one tiny part of a scene. One would have to completely control and dominate the lighting with controlled lighting in order to have any predicted knowledge of the accuracy of a rendered color. And as Andrew has pointed out you would have to measure every color everywhere so as to have two "patches" to actually compare, an impossibility. I heartily endorse those who seek more accurate control from their equipment, but this seems to me to be a quixotic quest for anything beyond testing your individual cameras and methods to achieve a precise white balance and improved rendering engine interpretation of the camera raw data. To those in scientific or museum situations, how colorimetricly accurate would your work be if you allowed mixed color temperature lights and colored reflections over any part of the subject being photographed? I think we can agree it would be nil, as it is standard practice to eliminate those very things when doing highly accurate, measured photography. Even the subtlest variation in color temperature between two light sources used to light a target for a profile creation makes for a very bad profile. How can one possibly overcome the variations in lighting over an uncontrolled scene in order to suggest colorimteric accuracy? Spend some time doing architectural photography with existing light, limited even to exteriors so as to avoid the extra problems with fluorescents of different age and type, tungsten sources, etc., and you will well know how different color temperature varies over a scene. Scene white balance is always a compromise of individual, perceptual selection. Thanks to all. Jeff Stevensen

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Re: Colorimetric Accuracy in the Field
by Henry Davis 08 Jun '13

08 Jun '13

Thank you, that's interesting and prompts me to ask: do colorimeters/ spectrophotometers attempt to mimic the human observer? I suppose there can only be a claim for mimicking - for how could it ever be verified? But we use them for measuring and determining a colorimetric match so we have to rely on the claim because besides that there is only subjective observers. Or we rely on both. My question about a measured match between two samples that don't match visually is still important to me and I think the answer puts a lot of stress on how colorimetric accuracy is defined. Henry Graeme wrote: Henry Davis wrote: > Nobody is saying that the illuminant isn't a hugely important factor. The main reason that the illuminant is a factor is that many/most cameras aren't colorimetric. By that I mean that their spectral sensitivities don't match a human observer. If they did, and their (light level) linearity was known, then (by definition) they'd be a high spatial resolution colorimeter. The practical situation is analogous to the one with cheap display colorimeters: They can be very accurate with a correction matrix if the spectral nature of the samples they are reading is known. With a display device that has colors that are (largely) a liner combination of the three primary spectra, a matrix does nicely. For a camera, it can't be that easy, because real world object colors are composed of many metamers, and the spectrum hitting the camera sensor is that times the illuminant spectrum. So a "calibration" matrix can fudge it for a range of expected object spectra x expected illuminant, but ultimately it's going to work the best over the widest range of conditions if the camera spectral sensitivity is closer to a human observer. It would be interesting to know which current cameras best fulfil this ideal :-) Such a camera would capture "what you see" with much less need for manual post capture tweaking. Graeme Gill.

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