CHROMiX

Metamerism

Hi all,

I have created a ICC profile for a Canon Pixma using Fine Art Paper.
The profile came out with heavy metamerism, green cast on neutral tones.

I have already tried to rebuild the profiles using all the different Viewing Sources in profilemaker, but it only reduced the effect slightly.

Any suggestions how to get rid metamerism will be appreciated!

Thank you.
Bill

Bill,

Based on your description, sounds like your dealing with an issue other than metamerism.

Please give details of your workflow.

Include info on your RIP, Measuring Device, Profiler and what type of profile you’re creating (RGB or CMYK).

If you’re not using a RIP, what graphics application are you printing out of?

Gotta give the details if you’re going to get an informed response…

Hi Christopher,

Thanks for your reply.

I am not quite sure if its metamerism to. I will try to decribe it:

  • The cast is Green, appears only in neutral B&W prints. Not visible or noticable in Color Prints.

  • I think the Print looks good under daylight, i am not 100% sure. My eyes easilly can fooled knowing the print is Green.

  • The cast is Heavy Green under Fluorescent or incandescent.

  • When i spot measure parts of the print with the spectro, returns perfect neutral measurements.

No RIP just the Canon Pixma Driver, EyeOne, Profilemaker 5, RGB Profile.

Photoshop.

The mystery is when i build multiple versions of the profile in different temperatures, from 2000K up to 9000K, all of them return the same Green Cast. In 9000K range the cast is a bit less noticeable.

I have measured the light in the room using EyeOne light head, its about 3500K. I build a profile with 3500K, and still the cast is there! :open_mouth:

If anyone cares to examine spectral measurement file or the ICC profile, i will be happy to send them.

Thanks,

regards,
Bill.

Grays are sometimes tough especially when you have to run through an RGB print driver.

Does the green cast show up when you soft proof the image on your monitor or is it only there after it prints?

That would make me think something’s up with the spectrophotometer calibration.
I assume your calibration pad on your Eye One is clean.
If you’re spectro is feeding bad data into Profile Maker then you’re certainly well aware of the outcome of that.

However, it could be the behavior of the inks. It kinda sounds like metamerism. Have you had success with this in the past?

Let’s see … if the profile is printing greenish, then it’s overcompensating due to the spectro reading too much magenta, right?

You have probably done this already but:
Measure a Kodak gray card and also measure the white side of the card (or even a white sheet of paper).
See what the Lab* values read. Do they lend themselves towards red?

Good luck getting this worked out.
I’m about to buy either a Canon or Epson printer myself. I use big VuTeks right now so my knowledge of printing through RGB drivers is minimal. I’ll be watching this thread with interest as I want to print black & white images on my new printer, too.

Does your paper fluoress under a UV light? (Are there any optical brighteners in the paper?)

Hi Richard,

Proof shows neutral. The cast is only in the Prints.

Calibration of the spectro is good. I have measured a gretag colorchecker. Grays and other colors are perfect.

No optical brighteners on the paper. Its a Hahnemuhle Photo Rag.

I had great success with other papers with the same printer including glossys with optical brighteners!

Thanks a lot,

regards,
Bill.

Bill,

The Photo Rag does contain optical brighteners - and it should (in my experience) trigger the “Correct for Optical Brightener” option in PM Pro.

There is the possibility (and I even venture to say, probability) that your issue is related to either the testchart being printed without all color-management (CM) turned off (this includes both PhotoShop color-management settings as well as Canon Pixma CM settings), or the custom profile is not being properly applied due to incorrectly applied CM settings in PhotoShop and/or Canon Pixma print driver.

Printing out of a graphics application using an OEM printer driver often complicates the task of setting up an error-free CM workflow.

Indeed, there is optical brighteners in PhotoRag.
But think it didn’t trigger profilemaker’s “correct for optical brighteners” option. I will check again.

It may be the source of the problem.

Thanks Christopher.

regards.
Bill.

Hmmm, PM’s Correct for optical brighteners option is disable.
Anyone knows how can i trigger it?

thanks.

Bill,

The threshold at which the OB Correction is triggered is not user adjustable.

Either your Spectrophotometer “sees” enough OB to exceed the threshold, or it does not.

In other words, one spectrophotometer calibration might be such that it is more sensitive to the OB while another spectrophotometer’s calibration is less sensitive.

Typically, a yellowish color cast (not green) is the result of OB effect in a non-corrected situation.

At this point, I recommend you don’t get hung up on the OB Correction trigger issue - explore the CM settings possibility that I suggested.

How long have you owned your Eye-One? Gretag recommends the device be returned for annual re-certification.

CM settings are correct.
I double check them, and printed the targets twice.

It’s close to the year. Maybe is good time for a visit in GMB.

regards,
Bill.