August 2014 - colorsync-users

The color of gray
by Peter Miles 04 Sep '14

04 Sep '14

Hi List members. I'm in the process of doing some spring cleaning. I'm pulling out some my old ideas that around color that I haven't examined for a while and asking myself if they are really correct. I'd appreciate it if you would read the following and kindly point out any misunderstandings / half-understandings on my part. The Color of Gray I am a bit suspicious of my current ideas around the concept 'gray' after asking myself if the following was really true... "That in an editing RGB color spaces, such as AdobeRGB 1998 and ProPhoto RGB, that 'equal RGB pixel values equal gray'. QUESTION 1 My current understanding is that this statement is true. But they are gray only relative to the white point of the colorspace. Because AdobeRGB 1998 is D65 and ProPhotoRGB is D50 the color of ProPhotoRGB 'gray' is different to the color from Adobe RGB 1998 'gray'. I attempted to test this (expecting to fail) by making up some gray ramps in photoshop in both ProPhotoRGB and AdobeRGB. I wasn't too surprised to see no color difference between the grays of ProPhotoRGB and AdobeRGB 1998. My understanding for this failure to see a difference is that the 'whites' of both colorspaces are being scaled relatively colorimetrically to my monitors white. Is this right? QUESTION 2: So am I correct in the following My Eizo monitor being set to 5000K will show me the color of the gray in ProPhotoRGB (D50 white) more or less correctly, in an absolute sense. And when my Eizo monitor is set to 5000K, the monitor color displayed for my AdobeRGB 1998 grays is incorrect. In an absolute sense. In that the grays will be displayed warmer than they should be given that Adobe RGB white is D65. QUESTION 3: I'm not near my printer to test this just now, but I'd expect AdobeRGB 1998 and ProPhotoRGB gray to print gray with different color with absolute colorimetric rendering? Thanks for your time. Regards Peter Miles

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Epson 10000XL scanner and i1 profiler
by Peter Miles 04 Sep '14

04 Sep '14

Hi List members. I have an epson 10000XL flat bed scanner. I made a reflection scan ICC profile with i1profiler and an xrite color checker chart as a target. It's an improvement on the factory defaults for sure. Question1: i1profiler question Is there any way for me to use a custom measurement of my actual color checker cart rather than i12profiler defaults? Or are the are the default target measurements not likely to differ that much from my color checker chart? Question2: Epson 10000XL problem (a little Off Topic) I am scanning textured water color paper. However my My Epson 10000XL reflection scanner in no-color-adjustment mode is clipping some whites values, so I'm not able to acquire the scan of the textured paper with all the paper surface details intact. Is looks to me like a scanner hardware/firmware issue as there seems to be no setting available to reduce the basic exposure in no-color-adjustment mode. Anyone else with a Epson10000XL? Is this just my scanner? Maybe there is some calibration strip cleaning / re-calibration thing I can do to the 10000XL to stop the white-clipping? Your advice appreciated Regards Peter Miles

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Re: Epson 10000XL scanner and i1 profiler
by Martin Orpen 01 Sep '14

01 Sep '14

On 31 Aug 2014, at 17:52, Ben Goren <ben(a)trumpetpower.com> wrote: > And that's all assuming you're limiting yourself to the Canon 5DIII. If you're doing oversized high-resolution art reproduction for commercial work, you're going to be using much higher resolution gear, and at least in medium format. There're many off-the-shelf offerings of at least 80 megapickles, and your budget is the only limit past that. See my previous post for the *requirements*. I’ll add that I think that high resolution capture using medium format is also seriously deficient because of moiré issues. An example that comes to mind is photographing bird feathers. If you stick them in front of a studio back that can capture <250MB RGB files and take close up shots, take a detailed look at the individual barbs. I’ve found the weirdest artefacts generated by the cameras — bands of in- and out-of-focus image (in a sharp shot) or patterning like tiny little swastikas instead of real detail. Stick them on the Lanovia’s scanner bed and you get exactly what you’re expecting — sharp detail without moiré issues. Artwork for me includes stuff like etchings, engravings, woodcut and linocut etc. 300 dpi capture and funky anti-moiré issues aren’t good enough. -- Martin Orpen Idea Digital Imaging Ltd

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Re: Colorsync-users Digest, Vol 11, Issue 109
by Gerry Yaeger 28 Aug '14

28 Aug '14

On Aug 28, 2014, at 12:00 PM, colorsync-users-request(a)lists.apple.com wrote: Hi Peter, I am using Silverfast AI Ver. 8 on a consumer Epson 3200. In the histogram panel is an expert button that allows you to back off the highlight exposure to eliminate any clipping. You should have that setting. Click on what looks like a graduation cap. Best wishes, Gerry Yaeger www.thedigitlcoach.com > ------------------------------------------------------------------- > > Message: 1 > Date: Thu, 28 Aug 2014 09:00:51 +1200 > From: Peter Miles <P.Miles(a)massey.ac.nz> > To: "'colorsync-users?lists.apple.com' List" > <Colorsync-users(a)lists.apple.com> > Subject: Re: Epson 10000XL scanner and i1 profiler > Message-ID: <6832ED68-1296-44B6-B4D8-7D0A8A8DC1CD(a)massey.ac.nz> > Content-Type: text/plain; charset=us-ascii > > Thanks Mark and Ernst. > Your feed back has been very helpful. > I downloaded a trial version VueScan and outputted a 'Raw format" scan of the water color paper. > Photoshop clipping level display show the same clipping of paper texture I have been seeing with EpsonScan in 'no color adjustment' mode. > and silverfast histogram. So it looking more like a hardware calibration issue. > > second 10000xl > I remembered that there is another 10000xl scanner on campus, and it's only a year or two old. > I scanned the same sample of water color paper with epson scan with 'no color adjustment' and it too clipped the paper texture in almost exactly the same way and extent as my 10000xl. There is a third 10000xl that I might be able to get access to. But with both 10000xl's I've tried so far doing exactly the same thing to my water color paper texture, my issue is starting to look more like a 'Feature' of the Epson 10000xl rather than a mistake . > > > Regards > Peter Miles > > >

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BabelColor PatchTool
by Ken Fleisher 26 Aug '14

26 Aug '14

When using BabelColor PatchTool for evaluating profile gamut and monitor performance, what exactly is happening when you are using a monitor such as an Eizo where the LUTs are uploaded to the monitor? If I use the Gamut Tools and Display Check, I need to select the destination profile. When I select the monitor's profiles (created with basICColor Display 5), of course the profile does not actually contain the LUTs. So how accurate is the Clip Check in Gamut Tools and the various stats that result from a Gamut Check? Is there some other method for testing these monitors performance when the profile does not contain all of the necessary information? Thanks. Ken

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Re: 22" low cost monitor
by tlabarbera 19 Aug '14

19 Aug '14

>>Ken Fleisher <PT_Ken(a)netbox.com>: I'm looking for 22" monitor recommendations. I have an Asus PA248Q which I've been pleased with--my budget couldn't swing for a NEC this time. I took a bit of chance because I'd read a number of reviews that mentioned backlight issues with the PA248Q but the one I ordered has been fine. The price was certainly right...'-}} Take a look and see what they have--click on the "IPS Monitor" option and there are some 22" and also 23" (might fit in a pinch?): http://www.asus.com/us/Monitors_Projectors/ Their "PA" line is Asus' answer for "professional" level monitors but I don't think there is a 22" PA model. Hope the above proves useful... Terrie tlbtlb(a)mail.com

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22" low cost monitor
by Ken Fleisher 19 Aug '14

19 Aug '14

I'm looking for 22" monitor recommendations. The requirements are 1. Low cost — $300 or under 2. Reasonable color – I'm not looking for high end color matching, but I don't want something that can't be calibrated either. The Dell ultrasharp monitors with Premier Color are satisfactory, but there are no longer 22" models. 3. 22" size 4. Not Dell (only because they no longer have a 22" model with Premier Color) Does anyone have any suggestions? Thanks. Ken Fleisher

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Phosphors
by Robin Myers 16 Aug '14

16 Aug '14

From: Robin Myers <robin(a)rmimaging.com> Subject: Phosphors Date: August 8, 2014 at 6:31:58 PM PDT To: Steve Jenkins <sj9000(a)comcast.net> > Oh, while we're on the subject, correct me if I'm wrong, but aren't the fluorescent agents, used for OB, absorbing UV, which we pretty much can't see, and the "agent" emits light at a lower frequency, to a part of the spectrum we do see -- which happens to be blue? Obviously there are phosphors out there that can fluoresce across the full spectrum(remember CRTs). So, is it the cost that prevents OBs from being full spectrum? Or some kind of energy issue ( i.e. CRTs used high energy electron beams to excite the phosphors)? You are correct in how the optical brighteners (OB) or fluorescent whitening agents (FWA) in paper operate. CRTs used three phosphors in checkerboard patterns or striped arrays to produce colors when activated by one (e.g. Trinitron) or three (traditional) electron beams. The blue and green phosphors were broadband, the red phosphor was usually one based on rare-earth elements and produced several narrow band emissions. Most white LEDs are made with a single broadband yellow phosphor excited by a blue LED. This works well for lighting where the color rendition is not very important such as architectural lighting, street lighting, flashlights, etcetera. These LEDs are usually deficient in cyan and red emissions but seeing is more important than color quality with these LEDs. Now that LEDs are starting to be used for retail purposes where the color is very important such as clothing displays, meat markets, cosmetics, etcetera, the LED manufacturers are beginning to use two or more phosphors to improve the color rendering properties. On that same topic, fluorescent lamps use a similar method for creating visible light, just substitute UV from excited mercury vapor for the blue LED. Continuing that parallel there are fluorescent lamps with one, two or three phosphors. In the CIE list of standard fluorescent illuminants the lamps usually used for color tests are the F2 (single phosphor, cool white fluorescent), F7 (dual phosphor, D65 simulator) and F11 (triple phosphor, Philips TL84, Ultralume 40) lamps. More phosphors are ocassionally used to improve the color rendering such as in one viewing booth manufacturer's lamps where six phosphors are used to produce a high color quality light source. I encourage everyone to learn more about light by experimentation. Some experimental supplies can be found at Edmund Scientifics (http://scientificsonline.com) Educational Innovations (http://educationalinnovations.com) or other experimental supply vendors. Try diffraction gratings to see the spectrum (some vendors offer glasses with diffraction grating lenses), or a cheap spectroscope (about $10) with a scale for getting a wavelength reading, then get out and measure the world. You might be surprised by what you will find. Robin Myers rmimaging.com

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X-Rite EyeOne iSis with M1 option
by Roger Breton 14 Aug '14

14 Aug '14

Is there such thing yet? We have i1pro2 with M1 option. Couldn't it be just a firmware upgrade? After all, the iSis already has the same LED light sources as found on the i1pro2. Or, will we have to wait for a new "M1" iSis from X-Rite? Best / Roger

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Re: X-Rite EyeOne iSis with M1 option
by Mike Strickler 12 Aug '14

12 Aug '14

Hi Ernst, I haven't been following this discussion and didn't see Gary's post, but I can tell you that I had this conversation with Tom Lianza and Ray Cheydleur at X-Rite some time ago, and if they are looking in they might fill in the details. Short answer is no, it is not a simple retrofit for the iSis. The scarcity of M1-capable instruments on the market is an indication how nontrivial this design change likely is. Best, Mike Mike Strickler MSP Graphic Services > > ------------------------------ > > Message: 5 > Date: Mon, 11 Aug 2014 10:53:42 -0700 > From: Ernst Vegt <evegt(a)shaw.ca> > To: colorsync-users(a)lists.apple.com > Subject: Re: X-Rite EyeOne iSis with M1 option > Message-ID: <B45C426B-18EA-432B-86B7-BE9BFFB434EE(a)shaw.ca> > Content-Type: text/plain; charset=windows-1252 > > Dear Group, > > It seems that there has not been a definitive answer to Gary Scott's request, namely, will there be a way to provide M1 measurement data via a hardware upgrade to the X-Rite iSis? Could this not be done by simply replacing one of the two bulbs and/or possibly a change in software? > > I for one (there you have it, a new X-Rite product - “i4One") would be happy to get on the M1 bandwagon, but not at $3K - $4K or thereabouts to replace the iSis. I believe this would very much slow down the adoption of M1 IMHO. > > Many thanks for any insights, > Ernst Vegt > > > ------------------------------ > > _______________________________________________ > Colorsync-users mailing list > Colorsync-users(a)lists.apple.com > https://lists.apple.com/mailman/listinfo/colorsync-users > > End of Colorsync-users Digest, Vol 11, Issue 99 > ***********************************************

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