Re: Current Crop of US Reference Colorimetric Standards
Re: Current Crop of US Reference Colorimetric Standards
- Subject: Re: Current Crop of US Reference Colorimetric Standards
- From: Roger Breton <email@hidden>
- Date: Thu, 17 Jan 2002 21:22:13 -0500
Henrik,
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ISO 12647 is also endorsed by the US, so what would you want with a
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separate standard ?
>
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There should be a firmer link between the ECI list and the ColorSync
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Users List to avoid standards splitting up for lack of one-on-one
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relations between people speaking different languages and all living
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on deadlines.
>
>
Just my ten cents.
I compared closely the Lab coordinates of ISO-12647 to that of SWOP (the
only published colorimetric data for anything US, really, to my knowledge)
and I find the difference just on the cyan, for example, disturbingly
"large". Maybe I have the wrong data but, quoting from Annex B of the
ISO-12647-2 I have (unfortunately, I am missing pages 4,5, 6 and 10 at the
present) :
Cyan Type 3 Lab = 55/-30/-39 (c* 49 , h 232)
versus
Cyan TR-001 Lab = 56/-37/-40 (c* 55 , h 227)
there seems to be too much difference between the two cyans. And even if I
look at Type 1 paper, the chroma of the cyan if 54 and the hue angle is 240
(which is too blue compared to SWOP). A difference of 8 Delta E.
The magentas are closer in hue angle (355 vs 357) and in chroma (71 vs 68)
but farther in lightness (43 vs 47).
The yellows are not so different.
But all in all, I have a hard time accepting that ISO-12647 Type 1 paper
could be used as a production profile for US sheetfed printing condition?
I want to find documented colorimetric standard for US SheetFed and I won't
use a Matchprint profile as a production profile in my ICC workflow. Unless
I can be convinced to the contrary. On the other hand, ISO-12647 is
published colorimetric data that is hard to ignore.
Could anyone argue that SID on a SheetFed good glossy sheet yields a larger
gamut volume than SWOP and that, because the C* for all three CMY primaries
is higher than their SWOP counterpart?
I just learned that the initial test run for the GraCol colorimetric
standard was turned down because not suitable for the CGATS?
So, we'll have to wait longer.
Any opinions?
Roger Breton
Quibec Institute of Graphic Communications