Re: ECI 2002V or 2002R?
Re: ECI 2002V or 2002R?
- Subject: Re: ECI 2002V or 2002R?
- From: Henrik Holmegaard <email@hidden>
- Date: Sat, 28 Sep 2002 10:18:09 +0200
On September 27, 2002, at 16:16 Europe/Copenhagen, Jack Kelly Clark
wrote:
>I'm starting to make cmyk output profiles with ProfileMaker 4.1. The
new 1485 patch test charts
>are impressive >(thank goodness for the Spectroscan).
>However, the documentation for these new test charts is a bit sparse.
The question is, which
>chart should one use? I'm about to profile a Heidelberg DI press and
was wondering which
>of the two ECI 2002 charts would be the best choice?
Choosing a test chart is a bit like choosing a black replacement
strategy. The type of test chart has to suit the type of process just
as the type of black replacement does, so there are no hard and fast
answers.
IMO a standards-based test chart has advantages over non-standard test
charts, and the ECI2002 test chart which is an IT8.7-3 super-set should
where possible be used in place of the IT8.7-3 which has always
attracted criticism for the way it samples a print color space.
First, the ECI2002 should be used for the proofing process. And
proofing profiles should be built with the highest possible resolution
in the B2A1 table.
Second, the ECI2002 should be used for the printing process and
profiles be built for the highest possible A2B1 resolution.
Then things get to be process-specific and instrument-specific.
There is a long-standing concept in the German printing industry that
scrambled patch layout on test charts helps smooth over the impact of
differential ink delivery in ink zones across the width of the printing
press, especially when several test charts are printed across the
format and the measurements averaged. Examples of this concept of
arbitrary patch layout are the GMG Weihing proofing RIP chart and
Heidelberg Printopen scrambled IT8.7-3.
As the IT8.7-3 and ECI2002 charts are / are going to become standards,
the systematic layout (as opposed to scrambled layout) won't go away.
It seems to be a concept built into the standards process -:). But on
the other hand there is no compelling reason to use a good test chart
in a maybe less practical way.
The iCColor x-y chart reader supports a scrambled ECI2002 layout. When
the slowest, two part version is measured on OS 10.2 it takes 16
minutes for 1500 patches. The one part version is a couple of minutes
faster. The SpectroScan x-y chart reader supports a systematic and a
scrambled layout.
I would choose the scrambled layout. Long-winded reasoning, one-line
conclusion.
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