[argyllcms] Re: RGB Printer Profiling / Issues with Blacks and Shadows

  • From: Klaus Karcher <lists@xxxxxxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Sat, 06 Aug 2011 20:36:34 +0200

Andreas Hebeisen wrote:
Printed from Photoshop CS 5:
The print looks OK, compared to another print made with an ArgyllCMS-profile, 
Photoshop etc. they're very, very close.

Sample patch reads:
   D50 Lab: 18.765331 0.820211 1.448157
(Since this is a fresh print, the black patch isn't as dark as it could be.
But this is OK. Within 24 to 48 hours it will become darker and will finally 
reach a value close to the print I listed first.)

And finally the Aperture 3.1.3 Print:
This is the ugliest print I've ever got from my machine. ;)
There are just reds and yellows. But when I look at the LAB visualization in 
ColorSync, this seems to be what you've intended.

Sample patch reads:
   D50 Lab: 47.894951 67.564971 36.821702

Now I'm anxious to hear your conclusions from this test.

In the test profile I replaced every tag but the B2A0 tag by more or less "deformed" tags.

the A2B0 tag adds red to the image
the A2B1 and B2A1 add green to the image
the A2B2 and B2A2 add blue to the image

As you observe a strong red cast there must be a perceptual transformation /from/ your printer profile to some other profile somewhere in the Aperture print workflow.

Klaus

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