Luminous Landscape Forum

Raw & Post Processing, Printing => Colour Management => Topic started by: Chris_Brown on October 21, 2009, 11:13:27 am

Title: Which GRACoL 2006 and SWOP 2006 profiles are correct?
Post by: Chris_Brown on October 21, 2009, 11:13:27 am

When comparing the GRACoL 2006 and SWOP 2006 ICC profiles from Adobe (http://www.adobe.com/support/downloads/detail.jsp?ftpID=4074) and GRACoL (http://www.idealliance.org/industry_resources/branding_media_and_color/gracol) using the ColorSync Tool, I see that the gamuts for the respective profiles are completely different. Does anyone know why they're different and which versions are correct?

In my screen grabs, the gray mesh represents the Adobe versions.

GRACoL comparison:
[attachment=17388:GRACoL_Comparison.jpg]

SWOP comparison:
[attachment=17389:SWOP_Comparison.jpg]

Title: Which GRACoL 2006 and SWOP 2006 profiles are correct?
Post by: Chris_Brown on October 25, 2009, 10:49:31 pm

No one knows?

Title: Which GRACoL 2006 and SWOP 2006 profiles are correct?
Post by: jjlphoto on October 26, 2009, 09:32:58 am

The axis's are in different orientations. Rotate one or the other and then compare.

Title: Which GRACoL 2006 and SWOP 2006 profiles are correct?
Post by: Chris_Brown on October 26, 2009, 12:44:38 pm

Quote from: jjlphoto

The axis's are in different orientations. Rotate one or the other and then compare.

This is incorrect. The ColorSync utility automatically aligns the axes.

Title: Which GRACoL 2006 and SWOP 2006 profiles are correct?
Post by: jjlphoto on October 26, 2009, 04:35:41 pm

do you mean in each shot, or comparing shot 1 to shot 2

Title: Which GRACoL 2006 and SWOP 2006 profiles are correct?
Post by: Chris_Brown on October 27, 2009, 08:39:35 am

Quote from: jjlphoto

do you mean in each shot, or comparing shot 1 to shot 2

My comparison is shown within each shot/graphic. The top one being a comparison between GRACoL color spaces, the bottom being a comparison between SWOP color spaces.

Title: Which GRACoL 2006 and SWOP 2006 profiles are correct?
Post by: Czornyj on October 27, 2009, 09:09:34 am

I'm not familiar with US printing standards, but it may be a matter of different data sets - in Europe we have different characterization data sets for standarized printing conditions, created with small (IT 8/7.3 918p), medium (ECI2002 1485p) and large (IT8/7.4 1617p) CMYK target. So for example - there are two sets of characterization data for CMYK sheetfed offset, paper class 1&2(coated), periodic screening - FOGRA39 (1485p), and FOGRA39L (1617p), and the different placement of color paches in both targets may result in slight gamut shape differencies.