Re: Epson and Agfa Yellow ink behavior
Re: Epson and Agfa Yellow ink behavior
- Subject: Re: Epson and Agfa Yellow ink behavior
- From: Henrik Holmegaard <email@hidden>
- Date: Wed, 28 Mar 2001 16:29:30 +0200
David wrote:
Correct, the only place you will see 100% Yellows is in vector files and page
layout defined CMYK colors (like Red= 0, 100, 100, 0) but people still wish
these colors to proof accurately. 100% Yellow is not the only color clipped
by AdobeRGB, try anything close to 100% Cyan!
Well, hmm... a Fuji transparency / Heidelberg QuickStep finescan
won't have the pure ink tank yellow of the press either.
But it's plain that once you stir RGB 'working spaces' into the pot,
then you don't have the full film gamut in CIELab any more, and
that's when to start thinking.
With device independence it's unnecessary to convert all the way to
the final output space off the bat, so you get to retain more gamut
in CIELab. When high bit TIFF Lab comes around, there will be less
pressure to loose gamut in the first stage of a device independent
workflow.
In choosing between CIELab storage and Adobe RGB storage, then Adobe
RGB clips rich reds, magentas, a big chunk of rich yellows, and
greens and cyans too in the HP5K gamut. ColorMatch and TIFFRGB are
roughly the size of a prepress monitor, and like a prepress monitor
these RGB interchange spaces can't hold a candle to the gamut of a
presentation printer.
Whether in CIELab or RGB interchange workflows, once the scan is
edited then the product is the digital original. So what is the best
representation of that?
a. The monitor ?
b. The presentation print (what the ECI guidelines call the
'idealized proof' though the fact that the presentation prints aren't
cropped to the same simulation offset gamut will make them mutually
different) ?
c. The proof print that crops the gamut of the presentation printer
to an offset gamut, say of a reference printing condition ?
Depending on developments in inkjet technology, it may get to make
sense to regard the inkjet presentation print as the best
representation of the digital original when handing off work.
It's odd to sit here with gamut comparisons and come away feeling
that the monitor-centric 'what you see is what you get' concept is
turning into an inkjet-centric one instead -:).
--
Henrik Holmegaard
TechWrite, Denmark