Re: U.S. Web Coated (SWOP)v2 vs. SWOP2006_Coated5v2
Re: U.S. Web Coated (SWOP)v2 vs. SWOP2006_Coated5v2
- Subject: Re: U.S. Web Coated (SWOP)v2 vs. SWOP2006_Coated5v2
- From: Marco Ugolini <email@hidden>
- Date: Sun, 06 Jan 2008 19:45:05 -0800
- Thread-topic: U.S. Web Coated (SWOP)v2 vs. SWOP2006_Coated5v2
In a message dated 1/5/08 10:36 AM, Roger Breton wrote:
> I feel your pain being caught into an "anti-color management group". It's
> true that people often don't want to hear the very words color management
> and ICC profiles pronounced together in the same sentence because that makes
> them sick. There has been many disapointments over the years with regards
> to CMS, for good or bad.
Hi Roger.
True, but let's not forget to add that a large number of those
disappointments originates from a *misunderstanding* of color management,
and from using it in a (pardon my non-Canadian "French") "half-assed"
manner. Like: converting instead of assigning a profile; stripping away
instead of honoring embedded profiles; assigning the incorrect profile;
converting to the incorrect profile; not soft-proofing correctly because the
monitor itself is not profiled, or even much too old and unreliable;
conflicts between tagged images and some RIPs; building output profiles of
poor quality or with settings inappropriate to the end use; etc.
> With the results that, understandably, users have become extremely
> cautious when it comes to move away from AdobeRGB and SWOPv2.
It makes me quite restless and impatient to see that after almost a decade
of color management technologies, so many people who ought to know better
are still mostly clueless. I include prepress houses and separators in that
statement -- though I wish to acknowledge that there are also many who are
highly capable and competent, and thankfully so.
>> The thing I find interesting/confusing is how the same CMYK values can
>> have such significantly different LAB values when comparing U.S. Web
>> Coated (SWOP)v2 to SWOP2006_Coated5v2.
>
> Doesn't that make life more interesting?
I am not sure what is meant by Todd as "significant". Without a number
specifying what qualifies as a "significant" difference (a 1.5 DeltaE 2000
value, for example), I am not sure how to weigh that assertion.
For example, if one assigns the US Web Coated (SWOP) v2 and
SWOP2006_Coated5v2 profiles each to one of two copies of the "TC3.5 CMYK"
reference file (which contains 432 patches), and then calculates the color
difference between the two sets in DeltaE 2000, using the Relative
Colorimetric intent in a worksheet in ColorThink Pro, the report says that
there are only 26 patches (6% of the total) with a value higher than 1.5
(the highest value being 1.89); 196 patches (45% of the total) have DeltaE
values ranging between 1.5 and 1.89, and 236 patches (55%) have values lower
than 1.
On the other hand, the same comparison done using the Absolute Colorimetric
intent reports 187 patches (43% of the total) with a value higher than 1.5
(the highest value being 2.61); 44 patches (10% of the total) have DeltaE
values higher than 2, and only 2 patches (0.46%) are higher than 2.5.
So, even the color differences registered using AbsCol are still lower than
the 3 DeltaE value that is customarily used as the cutoff between acceptable
and non-acceptable results.
It seems that even *assigning* either US Web Coated (SWOP) v2 or
SWOP2006_Coated5v2 does not produce *huge* differences in the results,
though there are indeed differences that may be considered visually
significant depending on where one places the DeltaE cutoff value (not to
mention that the DeltaE values will likely be higher when one uses color
difference formulas other than DeltaE 2000 -- but that's another story...).
Marco Ugolini
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