Great Pro-100 Profiles!

[Emulator]

I agree RogerB, that is, if we are talking about the greyscale aspects?



Chroma = C* =√(a²+b²) and is the deviation from neutral grey. The dotted green line represents 10 x chroma*, in the Gamutvision plot of PC42_KirkProGlossyTulip_D50.icm, so chroma appears to be exceptionally small.

A round trip test with WXProfileDump shows large deltaE values on any rendering other than Relative Colorimetric.

http://www.printerknowledge.com/att...4/?temp_hash=8835ccd27805428298595db03c199a79




However deltaE in colorimetric is good.

 

[RogerB]

Here is a colorthink analysis that speaks for itself:

I'm afraid that I'm not familiar with colorthink so I'm not quite sure what I'm looking at. However, in your colorthink2.jpg I can't quite reconcile the deltaE values that you have pointed to. I can't help wondering if these "errors" actually measure the difference between the printed (predicted) greyscale ramp and the perfectly neutral result. What is really puzzling is that the deltaE increases as L decreases. In other words, the error is at a mximum when there is little or no ink being laid down. This suggests to me that the "error" is simply the difference between the paper white and a truly neutral white.

I don't know what the second set of Lab values in the table represent, but they do look as if they are relative to paper white. I know that Gamutvision and Photoshop give Lab values relative to paper white, which is perhaps why the plot that I showed has negligible errors in neutrality. I think the paper white of the Kirkland paper is quite blue, so the absolute Lab values of a print would be far from neutral. Am I misunderstanding the results you have presented?

 

[Smile]

The profile was made without uv filter so the paper OBA makes it look blue for spectrometer, this may be the cause the print does not look as bad as colorthink report. Yes the colorthink evaluates the grayscale ideal values to the values the profile provides. So while the profile was made without uv filter when it should have been used the colorthing report is not very reliable. That is why I said that a proper certification should be made. If it was so easy to rely on synthetic calculations of software like colorthink the industry CMYK giant FOGRA would not have made print certification targets and tolerances.

What is really puzzling is that the deltaE increases as L decreases. In other words, the error is at a mximum when there is little or no ink being laid down. This suggests to me that the "error" is simply the difference between the paper white and a truly neutral white.

Delta E increases in this case because profile was made without UV filter. A bad practice is not to use UV-cut filter when it is needed.

 

[RogerB]

The profile was made without uv filter so the paper OBA makes it look blue for spectrometer, this may be the cause the print does not look as bad as colorthink report.

So are you saying that the profile may actually give good prints?

Yes the colorthink evaluates the grayscale ideal values to the values the profile provides. So while the profile was made without uv filter when it should have been used the colorthing report is not very reliable.

But I'm still not clear what the second Lab data set tells us. It looks very much like the Gamutvision result (relative to paper white) which says that the neutrality is good, relative to the paper white.

That is why I said that a proper certification should be made.

How would you actually do that? Would you print a greyscale step-wedge and then measure the actual Lab values? If you did that using Relative Colorimetric rendering, then wouldn't the paper white dominate the light tones? That is, the light tones would be far from neutral.

 

[Smile]

So are you saying that the profile may actually give good prints?

Possible, certification is the proper way to tell that.

But I'm still not clear what the second Lab data set tells us. It looks very much like the Gamutvision result (relative to paper white) which says that the neutrality is good,relative to the paper white.

How would you actually do that? Would you print a greyscale step-wedge and then measure the actual Lab values?

The cert test chart is made from grayscale values, color patches, and patches that contain 100% so to speak pure colors for gamut evaluation only.

If you did that using Relative Colorimetric rendering, then wouldn't the paper white dominate the light tones? That is, the light tones would be far from neutral.

The certification is printed in the rendering intent the customer desires, I do not force you to print in relative colorimetric at all. Usually the customer prints two rendering intents, Perceptual, Relative colorimetric. And chooses the one that passes the certification or has lowers error values. That is it, there is no need for debates.

Print with the settings you made the profile with choose different rendering intents and know the best configuration.

Professionals usually choose paper that is neutral, no color cast. So there is option for evaluation with true white, while there is also option for paper adapted white for all other papers. So there is no problem with paper white at all.

 

[peter D]

At this point I've finally refilled and reset all my CLI-42 carts with Precision Colors Inks a couple of times.
Earlier I had the common problem that many others have recorded. Slightly warm results.
Mikling's first set of profiles were no help. So I have made a couple of Colormunki profiles for a few papers and that solved the problem.

For the last several weeks, Mike has been very busy creating a full array of profiles which he has been adding to his ICC profile download page for the PRO-100.
I've downloaded and have installed all his Red River, Canon, Kirkland and Staples profiles and all I have to say is WOW! Perfect job!
Absolutely neutral and accurate results. I am afraid my Colormunki will be collecting dust for a while and will only be used for monitor recalibration every month.
I've viewed the gamut volumes of these profiles and their inherent very smooth shape of the 3D map, no holes or bumps, and right now there is nothing I would be able to do to improve their performance.

So if all you PRO-100 users have not used Mike's newest profiles for the PRO-100 I can say to you is to "RUN" over to the download page and grab them NOW.

Mike, I know very well the amount of work and effort you've put into these and I really appreciate what you have done. They are flawless. It's almost boring to print now!

Can't wait for the PRO-10 products.

Joe

Hi Joe,
I too have had good results with Mike's new profiles.
Do you know of any other profiles that have been created for Precision Colors inks?
I'm interested in obtaining profiles for a number of Ilford papers and in particular the Ilford Gallerie Smooth fine art paper.
Using the Canon Pro 100 profiles provided by Ilford with Precision Colors inks and printing on this particular paper there is a definite magenta cast.

Peter

 

[mikling]

peter D, if you are able to mail me two or three sheets of each paper, letter size, I will make the profiles for the Ilford. Please make sure that the papers are identified properly so others can also share the same profile.
My Canadian mailing address is on my website.

 

[stratman]

Mikling and Precision Colors -- you will find no better service!

 

[peter D]

Thanks Mike,
Fortunately most of the paper I currently stock is Canon brand and you have already provided profile updates for these.
I will send you some Ilford paper for generating additional profiles.
The only top quality Ilford paper I have at present is the Galerie Smooth Fine Art, the other two Ilford papers being 255 gsm paper priced more for everyday use.
Your top notch service and extensive technical support for your inks is much appreciated.

Peter