Re: Epson 5000 - RGB or CMYK
Re: Epson 5000 - RGB or CMYK
- Subject: Re: Epson 5000 - RGB or CMYK
- From: Roger Breton <email@hidden>
- Date: Sat, 08 Dec 2001 10:35:24 -0500
>
Profiling the Epson 5000 Stylus Pro.
>
>
It has been observed on this list that the Epson 5000 appears as an RGB
>
device on the Mac, so that the appropriate printer profile is an RGB
>
profile. The device (using Quickdraw) does the conversion from RGB to
>
CMY(K).
>
Abhay -
My experience tells me it's best to profile such EPSON printers as RGB
devices. One caveat, however, if you decide to follow this path, no matter
which profiling package you end up using (ColorBlind, ColorSynergy,
ColorFlow, PrintOpen, Monaco, PraxiSoft, ProfileMaker), you will INVARIABLY
have to edit the resulting profile. For there is something inherent in the
behavior of the QuickDraw driver itself combined with EPSON's undocumented
RGB to CMYK conversion that throws the prediction of all profiles I have
attempted off and that none of the packages I have used have been able to
capture?
In ColorSynergy, for instance, when I go in Preview and I select, let's say
some Matchprint profile as the Source and my custom EPSON RGB profile as the
Destination, after loading an IT8.7/3 Basic CMYK image to analyse the
conversion, pointing to a 100% Yellow patch in the Source pane, I can see
what device RGB values the software predicts for a given rendering intent
to best match that 100 Y. Say 255R 247G 235B. This is shown along with a
Delta E reading of X letting me know how close is the profile to matching
the Source color in the Destination space. Say 22 Delta E.
But then, in practice, in Photoshop, when I use the custom RGB profile to
match the same IT8.7/3 basic from Matchprint to my EPSON, and I print the
imange on my printer, when I measure the printed image (after letting it dry
appropriately), it turns out that the calculated RGB value is far from
yielding the predictd Delta Es : same disapointing result across ALL the
CMS packages I mentionned above! The yellows in particular are always
grossly mispredicted by several Delta Es. I have to use whathever CMS's
editing tools (in ColorSynergy, for example) to coerce the profile to give
RGB values that I know, on Output, best matches the 100% Yellow Matchprint.
I have to add that cyans and magentas are better predicted but not blues and
greens.
Let me know what you find out.
--
Roger Breton
Quibec Institute of Graphic Communications
Montrial (Quibec) Canada T. (514) 389-5061 F. (514) 389-5840
email@hidden