Problem: Copying Artwork & Matching Colours

[William Walker]

William,

If you will post an image by doing the following I will examine the profile and identify whether there are any gamut issues using Matlab. I have the tools to do so quite precisely.

1. Convert the image to Adobe RGB.
2. Attach (do not convert) the printer profile you are using. The image will change but don't worry about that.
3. Make a post here including this image.

If you wish you can also do the same but attaching the custom Colormunki profile and I can compare them.

Hi Doug

From Lightroom (ProPhoto) - "Edit In" - Photoshop. In Photoshop: "Edit" - "Assign Profile" - I chose my Colormunki Musuem Etching profile (Sample1) and the Hanemuhle Canned profile (Sample 2). I hope that is what you meant by "attach". If not, please explain!

Thanks
William

[William Walker]

William,

Everything seems to be perfect, that's what makes this issue so mysterious! I had tried to replicate your issue using virtually the same setup (OSX, LR, PA272W, iPF8300), but - no matter what setting, profile, rendering intent - I'm always getting quite similar results, unless I switch off the whole color management and print RGB numbers directly.
Do you have Photoshop? Please try to print this image using Canon PS Print Plug in (it's printing directly, "bypassing" iPF printer driver):
https://www.usa.canon.com/internet/portal/us/home/support/details/professional-large-format-printers/professional-photo-fine-art/ipf8400?tab=drivers#Z7_MQH8HIC0L88RB0AMD0F1Q42K25

BOOOM!

Print on the left....

[Czornyj]

Hi Doug

From Lightroom (ProPhoto) - "Edit In" - Photoshop. In Photoshop: "Edit" - "Assign Profile" - I chose my Colormunki Musuem Etching profile (Sample1) and the Hanemuhle Canned profile (Sample 2). I hope that is what you meant by "attach". If not, please explain!

Thanks
William

Why are you assigning HFA GE profile? If it's rendered to ProPhoto it should stay in ProPhoto!

BOOOM!

Print on the left....

The image is turned upside down on preview, so the correct image is on the right on the preview and on the left when you open it in the full size. Which one is the result from the PS Plug in?

[Doug Gray]

Hi Doug

From Lightroom (ProPhoto) - "Edit In" - Photoshop. In Photoshop: "Edit" - "Assign Profile" - I chose my Colormunki Musuem Etching profile (Sample1) and the Hanemuhle Canned profile (Sample 2). I hope that is what you meant by "attach". If not, please explain!

Thanks
William

That's fine but I don't see a Sample 1 or a Sample 2 attached to this post. Your subsequent post has 2 attachments. One in sRGB and one in an Apple RGB colorspace. Also, I am not asking for screenshots of printer settings or an image of the actual prints.

Let me restate my request for clarity.

1. Since your working space is ProPhoto edit the original image in Photoshop as ProPhoto.
2. Make 2 duplicates. Resize them so to take less space so the longest sides are 1000 pixels. This protects your IP.
3. Attach the printer's profiles (colormunki and manufacturer's) to image 1 and image 2, respectively.
4. Save both images in "tif" format using "save as."

[William Walker]

That's fine but I don't see a Sample 1 or a Sample 2 attached to this post. Your subsequent post has 2 attachments. One in sRGB and one in an Apple RGB colorspace. Also, I am not asking for screenshots of printer settings or an image of the actual prints.

Let me restate my request for clarity.

1. Since your working space is ProPhoto edit the original image in Photoshop as ProPhoto.
2. Make 2 duplicates. Resize them so to take less space so the longest sides are 1000 pixels. This protects your IP.
3. Attach the printer's profiles (colormunki and manufacturer's) to image 1 and image 2, respectively.
4. Save both images in "tif" format using "save as."

Sorry Doug! I forgot to attach the files!! Will do it in the morning.

[William Walker]

Why are you assigning HFA GE profile? If it's rendered to ProPhoto it should stay in ProPhoto!
The image is turned upside down on preview, so the correct image is on the right on the preview and on the left when you open it in the full size. Which one is the result from the PS Plug in?

Not sure how it ended up upside down...so the PS Plugin is on the left when viewed right-side up!

[Czornyj]

Not sure how it ended up upside down...so the PS Plugin is on the left when viewed right-side up!

Assuming that the PS Print Plug in prints correctly, let's find out if the bug is on iPF printer driver, or LR side. Please print the image from PS using regular driver (Cmd+P):

[William Walker]

That's fine but I don't see a Sample 1 or a Sample 2 attached to this post. Your subsequent post has 2 attachments. One in sRGB and one in an Apple RGB colorspace. Also, I am not asking for screenshots of printer settings or an image of the actual prints.

Let me restate my request for clarity.

1. Since your working space is ProPhoto edit the original image in Photoshop as ProPhoto.
2. Make 2 duplicates. Resize them so to take less space so the longest sides are 1000 pixels. This protects your IP.
3. Attach the printer's profiles (colormunki and manufacturer's) to image 1 and image 2, respectively.
4. Save both images in "tif" format using "save as."

Hi Doug - I have followed your instructions.  Not sure why I could not upload here, not Jpeg? Too large?
I hope this link works!
https://www.dropbox.com/sh/lkffz2nglpv1jx8/AABDij-BFr00SQsv_LmVo9coa?dl=0

[William Walker]

Assuming that the PS Print Plug in prints correctly, let's find out if the bug is on iPF printer driver, or LR side. Please print the image from PS using regular driver (Cmd+P):

The larger print is the one I did yesterday with the Canon Print Plugin. The smaller print I have just done through Photoshop. I used my Colormunki Profile with Relative Intent for both.

It is clear that, even though the prints are not identical, the "jade" that I have been looking for is sufficiently present. Compare this with the blue of one of my "problem Lightroom prints" underneath the small print on the right-hand side.

It seems to me that Lightroom is the source of the problem...

Added Later: I have just tried "16 bit Off" in Lightroom which had no effect on the prints coming out of Lightroom - still horribly wrong!!

[Czornyj]

So the LR bug is the main suspect. Are you using the newest LR CC 6.6?

[Mark D Segal]

So the LR bug is the main suspect. Are you using the newest LR CC 6.6?

What LR bug?

[William Walker]

So the LR bug is the main suspect. Are you using the newest LR CC 6.6?

2105.6 Latest (Last Week)

[Czornyj]

What LR bug?

Apparently there's a bug that makes LR print unconverted RGB numbers of an synthetic color space of the image (target like). All setting screen shots provided by William seem to be correct, the iPF PS Print Plug-in and PS with the printer driver prints correct, so it looks like some kind of LR bug.
It's quite weird, as I tested virtually same setup trying to reproduce this problem and didn't encounter any issues.

[Czornyj]

2105.6 Latest (Last Week)

Try to uninstall and install drivers and LR. Unfortunately I'm out of other ideas - everything looks ok, so it's either a LR bug, or I'm missing something...

[Mark D Segal]

Apparently there's a bug that makes LR print unconverted RGB numbers of an synthetic color space of the image (target like). All setting screen shots provided by William seem to be correct, the iPF PS Print Plug-in and PS with the printer driver prints correct, so it looks like some kind of LR bug.
It's quite weird, as I tested virtually same setup trying to reproduce this problem and didn't encounter any issues.

Interesting and strange, but I've never heard of or experienced this.

[Doug Gray]

Hi Doug - I have followed your instructions.  Not sure why I could not upload here, not Jpeg? Too large?
I hope this link works!
https://www.dropbox.com/sh/lkffz2nglpv1jx8/AABDij-BFr00SQsv_LmVo9coa?dl=0

Exactly what I needed. Thanks.

A few comments:

It's clear the big problem is on the printer side but not related to the profiles. Neither profile should result in the dark blue shift you are seeing on your prints. I would install Photoshop on a different machine and print the image there to see if there is some sort of driver issue. If possible use a Windows machine.

That said, there are lesser issues with the profiles. The custom profile exhibits some unusual non-linearity in the Cyan regions. I'm going to look closer at those. Also, the custom profile is a V4 profile while the canned profile is V2. That shouldn't affect Relative Colorimetric printing but you will get more consistent results when using Perceptual if you generate V2 profiles from the ColorMunki s/w. However, none of this explains the strong blue shift you are getting.

On the positive side the black point is around L=19 on both profiles with maybe a deltaE of 1 difference. This indicates the canned profile is not, incorrectly, incorporating a BPC inside the profile for RC. Some OEM profiles do this.

Also, the image itself exhibits a strong "S-curve" characteristic of output referred image capture. One side effect of this is that lower luminance are reduced further and high luminance regions are compressed. This is also evident in the capture with a colorchecker passport that was posted earlier.

More later.


I grabbed a cyan section from the right side of the ProPhoto image then ran a round-trip using Relative Colorimetric for the Custom and Canned profiles. These colors are roughly around the printer's gamut boundary. The attached image contains the histograms of the resulting deltas and the image section from the original in ProPhoto. Horizontal axis are the deltas.

The canned histogram exhibits typical behavior near a gamut boundary. I suspect the Custom, ColorMunki histogram looks like it does as a result of too few patches to create good profile LUTs.

However, this is a curiosity as the effects are still very small compared to the strong dark blue shift William is getting. The printer issue clearly needs to be resolved.

[Czornyj]

However, this is a curiosity as the effects are still very small compared to the strong dark blue shift William is getting. The printer issue clearly needs to be resolved.

Exactly - you don't need spectral measurements to see there's something very wrong going on here. My wild guess is it's rather LR releated than printer driver releated.

[Mark D Segal]

Exactly - you don't need spectral measurements to see there's something very wrong going on here. My wild guess is it's rather LR releated than printer driver releated.

I'll agree with you that it's a wild guess, because the problem is very specific, whereas if it really were LR-related, one would see more generalized issues across a wider range of images. LR operates in a very wide-gamut native colour space and the rest of its color management uses conventional ICC technologies. I think Doug is onto something with the gamut boundary business and why I made some specific recommendations above for printing on a wider gamut paper to see whether this solves the problem - notwithstanding your disagreement with this as a possible source of the problem :-).

[Doug Gray]

I've attached images in ProPhoto RGB for testing the color rendition quality. These are "Color test.tif" and "Color test RC.tif."  "Color test.tif" is designed to be printed using absolute colorimetry and contains a Colorchecker patch layout which should, when printed, look very close to a standard Colorchecker card. However, it's a 2007 CC and the darker blue/violet colors are faded a small amount so a correctly printed image may look very slightly faded there. It is a very small affect and is quite hard to see even side by side.

The "Color test RC.tif" image should be printed using Relative Colorimetric Intent without BPC selected and should produce the same image visually. This provides a way to check the workflow using RC which is a more normal workflow than Absolute Intent.

The blue/cyan patches below the colorchecker image have Lab colors in steps of 10 in the image's blue region. Their Lab values can be measured with Argyll and a Colormunki and should be reasonably close to the values printed on the chart with a typical variation averaging about 3 dE's being good and 5 dE's being marginal.

[Czornyj]

I'll agree with you that it's a wild guess, because the problem is very specific, whereas if it really were LR-related, one would see more generalized issues across a wider range of images. LR operates in a very wide-gamut native colour space and the rest of its color management uses conventional ICC technologies. I think Doug is onto something with the gamut boundary business and why I made some specific recommendations above for printing on a wider gamut paper to see whether this solves the problem - notwithstanding your disagreement with this as a possible source of the problem :-).

Well, I can print form LR without any issue, no matter how wide the operating gamut is. The problem is not in couple of ∆E's territory, the problem is night and day, dozens of ∆E difference, so it can't be gamut/profile/rendering releated.
As you can see, William can print ProPhoto rendered image from PS or PS print Plug-in flawlessly, while the result from LR is deep in the forrest. You don't need to be a color scientist to draw obvious conclusions.