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Author Topic: pink color cast on "white" border  (Read 4088 times)

digitaldog

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Re: pink color cast on "white" border
« Reply #40 on: January 18, 2018, 10:51:16 AM »

Well darn. I looked up my photoshop color settings and attached. Absolute is not selected.
And it shouldn't nor need to be. That's only going to be used IF you conduct a conversion to CMYK or RGB in "Mode Change" instead of the proper and more feature rich method: Convert to Profile. Then it bypasses the color settings to what you select there. Plus you can pick any RI and soft proof the results. And as stated, there's no Absolute Colorimetric option in Lightroom so this isn't really a necessary step. 
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Andrew Rodney
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Thenolands

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Re: pink color cast on "white" border
« Reply #41 on: January 18, 2018, 08:11:14 PM »

Ah - sorry I missed that; yes you did. This reverts the story back to the profile, because the profile specification includes the four Rendering Intents for handling out of gamut colours. I'm now wondering whether there is a problem with Relative Intent rendering of the White Point. Have you tried printing it in Photoshop with Absolute, which does not remap the White Point from the source to the destination? If the cast disappears in the Absolute print, it would seem to indicate a problem with the interpretation being applied with Relative.

Mark, I did a test print directly from photoshop using absolute colorimetric and the cast did in fact disappear! So does this settle it once and for all? If I were to get RR to either create a better/accurate profile or get a custom profile created then I should be good, no?
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Mark D Segal

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Re: pink color cast on "white" border
« Reply #42 on: January 18, 2018, 08:14:49 PM »

Mark, I did a test print directly from photoshop using absolute colorimetric and the cast did in fact disappear! So does this settle it once and for all? If I were to get RR to either create a better/accurate profile or get a custom profile created then I should be good, no?

This is pretty much what I was expecting to hear back. It does appear to indicate that something may be messed-up with Relative Colorimetric White point mapping in the CMM, which may be due to an error in the profile. While this evidence is not conclusive, it is indicative enough to advise RR that they should revisit this profile to see whether they can (a) replicate the problem, and if so (b) re-issue a corrected profile.
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Mark D Segal (formerly MarkDS)
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digitaldog

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Re: pink color cast on "white" border
« Reply #43 on: January 18, 2018, 09:08:43 PM »

It does appear to indicate that something may be messed-up with Relative Colorimetric White point mapping in the CMM, which may be due to an error in the profile.
Yeah, the profile itself (but not the CMM).
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Andrew Rodney
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Thenolands

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Re: pink color cast on "white" border
« Reply #44 on: January 18, 2018, 09:24:48 PM »

Sorry, CMM?
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digitaldog

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Re: pink color cast on "white" border
« Reply #45 on: January 18, 2018, 10:01:33 PM »

Sorry, CMM?
Color Matching Module (or Color Matching Method depending on who you ask). It's the part of the software that converts the data, the engine so to speak. Nothing you need to really worry about.
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Andrew Rodney
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Mark D Segal

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Re: pink color cast on "white" border
« Reply #46 on: January 18, 2018, 10:36:02 PM »

Yeah, the profile itself (but not the CMM).

Specifically, (Real World Color Management 2nd Edition, page 86) "The Color Management Module, or CMM, is the software "engine" that does the job of converting the RGB or CMYK values using the color data in the profiles.....The CMM provides the method that the color management system uses to convert values from source color spaces to the PCS and from the PCS to any destination spaces." (PCS is the Profile Connection Space). And yes, Andrew, nothing one needs to worry about. I was just trying to be precise about what happens under the hood and the role/importance of the information the profile provides to these calculations of the colour values that get printed. To be clear, I agree the user needs to be concerned about the profile, not the CMM.
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Mark D Segal (formerly MarkDS)
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digitaldog

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Re: pink color cast on "white" border
« Reply #47 on: January 19, 2018, 10:46:14 AM »

Specifically, (Real World Color Management 2nd Edition, page 86) "The Color Management Module, or CMM, is the software "engine" that does the job of converting the RGB or CMYK values using the color data in the profiles.....
Not just RGB to CMYK conversions.  ;)
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Andrew Rodney
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Mark D Segal

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Re: pink color cast on "white" border
« Reply #48 on: January 19, 2018, 12:09:20 PM »

Not just RGB to CMYK conversions.  ;)

Sure, but that's not what this quote from the book meant.
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Mark D Segal (formerly MarkDS)
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digitaldog

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Re: pink color cast on "white" border
« Reply #49 on: January 19, 2018, 12:23:09 PM »

Sure, but that's not what this quote from the book meant.
Isn't that what it said? I can look it up of course, I've got several copies. What does it mean?
Specifically, (Real World Color Management 2nd Edition, page 86) "The Color Management Module, or CMM, is the software "engine" that does the job of converting the RGB or CMYK values using the color data in the profiles...
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Andrew Rodney
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Mark D Segal

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Re: pink color cast on "white" border
« Reply #50 on: January 19, 2018, 01:01:04 PM »

Perhaps best you look it up and see what you make of it. But we're wandering OT. The main point is reply #42 emphasizing the need to look at the profile; the rest of it was just to explain the role of the profile relative to the conversions that take place in the CMM - as we agreed not something to be concerned about - with a good profile the CMM will just do its thing.
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Mark D Segal (formerly MarkDS)
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digitaldog

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Re: pink color cast on "white" border
« Reply #51 on: January 19, 2018, 04:34:07 PM »

Perhaps best you look it up and see what you make of it. But we're wandering OT. The main point is reply #42 emphasizing the need to look at the profile; the rest of it was just to explain the role of the profile relative to the conversions that take place in the CMM - as we agreed not something to be concerned about - with a good profile the CMM will just do its thing.
As I said, it's not something the OP needs to be concerned with. But since he asked about what a CMM is, and since the text applied mentioned only RGB to CMYK, I think he should now know that any conversion uses the CMM. Convert CMYK back to RGB, or Lab etc. And yes, it was OT but I'd hate the OP to believe a CMM is only used with one kind of conversion.
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Andrew Rodney
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Mark D Segal

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Re: pink color cast on "white" border
« Reply #52 on: January 19, 2018, 04:37:40 PM »

As I said, it's not something the OP needs to be concerned with. But since he asked about what a CMM is, and since the text applied mentioned only RGB to CMYK, I think he should now know that any conversion uses the CMM. Convert CMYK back to RGB, or Lab etc. And yes, it was OT but I'd hate the OP to believe a CMM is only used with one kind of conversion.

Completely agree, and I did not interpret the sentence I quoted as meaning there is only one kind of conversion. No doubt in my mind the authors did not intend that either. Perhaps I should have quoted more of their paragraph to better clarify the context, but I was trying to cut to the bone - however not into it  :-). Cheers.
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Mark D Segal (formerly MarkDS)
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Thenolands

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Re: pink color cast on "white" border
« Reply #53 on: August 13, 2018, 07:47:19 PM »

Update on this topic: Red River sent me a new profile and I would say it is better (as in less pink) but there is still ink being sprayed on areas of 255/255/255. Now, they said they used a printer close to my ipf8400 (not an ipf8400 itself) but really for the problem I am having the printer shouldn’t matter, I imagine.

I suppose the answer is to buy a DigitalDog custom profile 🙂
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