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Author Topic: Paid profiles exhibiting unique weirdness: banding & color shift  (Read 6857 times)

tvalleau

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Hi folks

I come here once every few years it seems, and this time I'm trying to chase down a mystery with a group of  profiles.

I recently paid a top-tier company to make custom profiles for me. I used PrintTool to print their target without Colorsync, Adobe or Epson messing with it. (The printer is a 9890.)

What happens with only these profiles, and it's across all of them, is this: 1) there is a color change in the cyan, and more obviously, 2) printed using Relative Colormetric (RC) intent, I get a banding of colors, some of which is quite obvious.

With perceptual, everything looks fine. Yes: I understand the difference between the two, and that's obviously in play here. The question is -why?-

I've switched between RC and percp tens of thousands of time over the years, using Epson profiles; my own profiles; paper mfgrs profiles, and I've never seen anything like this.

(My test image is the one with the clock in the upper left, and the sandbar in the lower right; strawberrys, yellow flowers, and the arches in the southwest. The pattern I see this in is at the bottom of the second column of images.)

I've uploaded a scan of the printouts, using the paid profile, an Epson profile and my own ColorMunki profile, all printed using RC intent. Epson and mine look as I've always seen; the paid one is out of whack.

I've dropped the profile into ColorThink, and it appears fine to me (although I could be missing something. I'm not a ColorThink expert.)

Now I've ordered an Xrite i1Photo Pro spectrophotometer to bump up my own quality level from the ColorMunki... and because I'm so puzzled by this, as is the provider of the paid profile. Someone in the QTR group on Yahoo suggested I come over here to see if anyone can explain why I'm seeing this only on these particular profiles, and have never seen it before.

I've attached the sample scan of the prints. It is also here:    http://cl.ly/image/1o0e3O2r1t0L

Note the different color on column A & B; the "banding" in C but also in the magenta next to B and red next to D.

Here is the profile, if you'd like to see it:  http://dlsi.biz/fc/Ep9890_EpPrmLustr.zip

If anyone here would care to take a moment to look at this, and enlighten me, I'd sure appreciate knowing what's going on.

Yosemite 10.10.3; 32 GB RAM; Photoshop CC (2014); PrintTool.

Thank you.

Tracy Valleau
www.valleau.gallery
« Last Edit: April 17, 2015, 01:03:52 pm by tvalleau »
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Wayne Fox

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #1 on: April 17, 2015, 02:26:37 pm »

Seems only two possibilities, either the target had some issues, or the profile creation had some issues.  Have you spoken to the company that made the profile?

Curious why you used Print Tool instead of the Adobe Color Printer Utility?  I would reprint the target from Print Tool and then from Adobe’s utility and see if visually there are any subtle differences.  Also curious about the target, how many patches?  Did you check the nozzles before printing the targets?

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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #2 on: April 17, 2015, 02:45:04 pm »

Thanks, Wayne. Greatly appreciate the reply.

Yes, I spoke with them at length, and they can't explain it.

I used PrintTool because the company's software generates a new target for each paper, with a special code on it. The default ppi embedded in the file is the wrong size to produce the needed 8x10 print, so each file needed to be resized (from 72 to 101 ppi.)  I had 24 profiles made, and chose to use PrintTool because it allows for on-the-fly resizing, while CPU does not.

Yes, the heads are working just file, and yes, I did print out a chart using CPU, and eye-balled it in comparison to the PT version. They looked the same to me, although eye-balling probably isn't sufficient at this point.

There are 928 patches; 729 are color, and the rest gray-scale.

I can add this info:
their profiles default to RC, while most others I've seen default (in the header) to perceptual. (I realize that shouldn't make any difference, but then I shouldn't be seeing this anomaly either...)

Their target comes with an embedded sRGB indentification.*** That's likely because their instructions for printing without color manipulation on the Mac were out of date, using the old sRGB to sRGB technique that no longer works.

I'm fairly sure that didn't enter into the actual printing, since I printed one out using thru a paper profile, and it didn't look remotely the same., and, as I noted, the CPU and PT versions were (at least to my tired old eyes) identical.

*** this is likely incorrect. See below.
« Last Edit: April 22, 2015, 04:08:51 pm by tvalleau »
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Wayne Fox

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #3 on: April 17, 2015, 05:47:45 pm »


Their target comes with an embedded sRGB indentification. That's likely because their instructions for printing without color manipulation on the Mac were out of date, using the old sRGB to sRGB technique that no longer works.

You may want to try and map the target in ColorThink and compare against sRGB gamut.  I suppose it’s possible that somehow in the process the files were actually clipped into the sRGB space.
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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #4 on: April 17, 2015, 06:17:41 pm »

Now that's an interesting possibility, Wayne. Thanks. I'll check into it, and report back. (I'm on my way out just now, so it may not be until tomorrow...)

Thanks.
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hugowolf

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #5 on: April 17, 2015, 09:31:34 pm »

Some thoughts…

By banding, I presume you are getting posterization, which is always a possibility with relative colorimetric.

928 patches isn’t a lot for a good profile, I’d look at it as a minimum. I do 1380 for even basic papers that I don’t use often.

Do the papers you have profiled have a high OBA content? That could make a significant difference, depending on the viewing conditions and the profiling process.

Brian  A
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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #6 on: April 18, 2015, 03:02:21 pm »

Hello again...
Forgive me as a beginner at ColorThink, but here's what I did:

First, it appears that my comment about an embedded sRGB profile was wrong, and I simply must  have gotten confused at some point, and accidentally applied one. My mistake.

Then, I opened the print target in PS: no embedded profile (sanity check)

Next, I open the print target in  ColorThink : no embedded profile

In CT, I used colorSmarts Guid, chose by tool - grapher / compare image colors with device gamut
compare the EPL.tiff to sRGB profile
They are identical - a perfect match.

So, Wayne, you were certainly on the right track. I would not have expected the target to perfectly match the sRGB contour, but the (view by) points  of the target lay perfectly on the (view by) wireframe of the sRGB system profile.

Now, in my ignorance, I'd have expected the target to be significantly larger than sRGB, else how would I ever get a profile that fully utilized the range of my printer (which is closer ARGB) otherwise?

Or do I simply not yet understand how a target is read and created? Shouldn't that target print (created by their software) been larger than sRGB?

Thanks for the hand-holding. it's humbling to think that I clearly understand this stuff, and find myself quite so lost. I appreciate the help.
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digitaldog

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #7 on: April 18, 2015, 03:13:57 pm »

Next, I open the print target in  ColorThink : no embedded profile
Then it’s impossible to say it’s in sRGB or otherwise to make any additional comparisons. CT doesn’t know what the RGB values are without an embedded or assigned profile, how could it? It can’t plot or provide Lab values either. IF you assign sRGB to the numbers, they will match, well sRGB.
Quote
I would not have expected the target to perfectly match the sRGB contour, but the (view by) points  of the target lay perfectly on the (view by) wireframe of the sRGB system profile.
Assign Adobe RGB (1998) and plot it against that profile. You’ll get the same results if I follow what you’re doing.
CT isn’t going to help you a lick unless you have the measurement data used to build the profile.
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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #8 on: April 18, 2015, 03:16:25 pm »

Hi Brian, and thanks for jumping in.

Yes, I considered calling it posterization at first, as the vivid light magenta column certainly looks like that. But closer examination of the image printed thru the resulting profile shows (in the red and green) areas where what should have been a smooth transition from light to dark, instead move from light to dark, to light, to dark, to light again, as if the gradation was re-arranged in small chunks.

True, that could be a form of posterization fooling my eyes, so I won't seriously disagree with the use of that term.

I've seen a lot of posterization in my time, and that said, what I have not ever seen is this happen like this from a RC conversion. As I understand it, colors within the gamut are not moved at all, and only colors outside the gamut are moved to the closest neighbor within the gamut. (To the edge, if you will). So I'd have expected -most- of the color to be within gamut, and no posterizing for the vast majority of the tone range.

That has been my experience with all the other profiles I have: I can switch between perceptual and RC with relative impunity, and certainly without what I'm seeing in the image I posted here.
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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #9 on: April 18, 2015, 03:21:37 pm »

 Thank you, Andrew. That completely makes sense. I might be able to come closer on Monday, when the new i1 Photo Pro spectrophotometer gets here. I'll see if it's possible for me to make a profile from one of the printed targets, and if so, how it compares in the same image test.

Do you have any suggestions as to how else I might nail down whether it's the printed target, or the profile that was generated from it?

I can use the paid profiles with perceptual intent, of course, but some of my work requires RC...
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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #10 on: April 18, 2015, 03:27:18 pm »

snip
928 patches isn’t a lot for a good profile, I’d look at it as a minimum. I do 1380 for even basic papers that I don’t use often.

Do the papers you have profiled have a high OBA content? That could make a significant difference, depending on the viewing conditions and the profiling process.

Brian  A


I neglected to answer the rest of your questions.  Yes: some of the papers have significant OBAs, some have none; however the effect, to greater to lesser degree, happens with all profiles on all the papers I've retested so far. The example I posted has what I'd call "medium" OBAs - it's Epson Premium Luster.

Of course, I'm using their software to generate a target for their automated reader, so I have no choice in the number of patches. Come Monday, I'll remember your advice as to the 1380 minimum. Thanks for that.

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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #11 on: April 18, 2015, 03:29:50 pm »

One last thing I tend to forget, is that not only does that posted image show "banding/posterization" but the cyans are significantly darker than are those printed thru the Epson and ColorMunki profiles. I'd assume that the two symptoms are related...
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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #12 on: April 18, 2015, 04:22:58 pm »

Just to make sure then: ColorThink will apply an sRGB profile to an image file if that image file is untagged? I ask because when I open the (apparently) untagged target and compare it to the AdobeRGB space, it (the target) is showing the smaller sRGB graph points within the larger ARGB...

Also, I've removed the Adobe CPU vs PrintTool from the equation by printing the target with each; scanning the print and layering the results in Photoshop, using difference. Got a nice, pure black result, so the printing software is generating the same thing regardless of which is used.
« Last Edit: April 18, 2015, 04:42:09 pm by tvalleau »
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digitaldog

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #13 on: April 18, 2015, 05:15:42 pm »

Just to make sure then: ColorThink will apply an sRGB profile to an image file if that image file is untagged?
It can’t produce Lab values which is the key. It ‘sees’ the RGB device values (R23/G66/B90) but those values are meaningless without a profile.
Take a target, assign two different profiles to the same numbers, ask to Plot List. You’ll get a different plot from identical device values but of course, differing Lab values.
Take the target and plot with and without sRGB, it appears the two plot the same so yes, it appears CT assumes sRGB for untagged numbers.
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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #14 on: April 18, 2015, 05:28:54 pm »

Thanks again, Andrew. CT's automatic use of sRGB on an untagged file is what had me confused before. The rest of your explanations jibe with what I (thought) I knew before, so that's of some comfort...  ;)

At this point, with the "banding" and the color shifts, I'll probably be better off waiting for the new i1Photo to come on Monday and see if the same thing happens to me.

Meanwhile, I'm happy to pursue other suggestions.

(My point in pursuing all this is two-fold. If it's somehow my error, I'd naturally want to know that, and 2) if their equipment is out of calibration or suffering the effects of age, I'm sure they'd want to know that as well.)

Thanks again everyone.
« Last Edit: April 18, 2015, 05:38:08 pm by tvalleau »
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Lundberg02

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #15 on: April 20, 2015, 01:50:39 am »

Maybe it's me, but your posted image doesn't show any problems, and the Paid looks better than the Epson.
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Rhossydd

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #16 on: April 20, 2015, 02:45:06 am »

Maybe it's me, but your posted image doesn't show any problems, and the Paid looks better than the Epson.
Really ? If you can't see that step in the magenta gradient marked as C you shouldn't comment any further on this.
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Stephen G

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #17 on: April 20, 2015, 05:18:25 am »


There are 928 patches; 729 are color, and the rest gray-scale.


This fact makes me suspect quite strongly that they are using the SpyderPrint system. I own it and have abandoned it, and I don't think a professional service should be using it.

My thoughts on the system are described here:
http://forum.luminous-landscape.com/index.php?topic=78431.msg630093#msg630093

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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #18 on: April 20, 2015, 01:42:13 pm »

Nope: not SpyderPrint (which I tried many years ago and abandoned instantly as well.)

As I noted, the profiles in question were made by a very well respected company, whose name would be familiar to everyone here, and I can pretty much assure you are not using SpyderPrint.  I have not mentioned the name because I'm still assuming it's something on my side of the equation.

I expect my new hardware to arrive in a few hours, and I'll try my own profile on Epson Premium Luster and see if the issue shows up in that one. (Of course, that won't prove anything about why theirs exhibits the problems.... )
« Last Edit: April 20, 2015, 01:44:05 pm by tvalleau »
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tvalleau

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Re: Paid profiles exhibiting unique weirdness: banding & color shift
« Reply #19 on: April 20, 2015, 01:49:51 pm »

For those who have been using spectrophotometers for a while now: is it possible for the lamp to age, and induce a color-shift during reading? Could there be any other kind of issue with their hardware that might cause this?
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