TTBOMK there still aren’t any RGB standards for print or proof accuracy, as
there are for CMYK with the various ISO12647, IdeAlliance, Fogra, etc
requirements for print and proof validation but I’ve found an incredibly
useful site who does exactly what it is you’re looking for, specific to RGB
fine art printing. Better still, the dE values they use are much more
inline with what most ‘typical’ fine art printers would expect from their
profiles and prints. As in, much lower than, say, the ISO12647
requirements.
And the best bit is that they provide extensive documentation, so much that
it’s super easy to duplicate their processes and procedures and the only
thing you miss out on is the convenience of being able to just measure some
patches and get a nice and pretty pdf with the results. But it’s easy
enough to put this info together by oneself and get the same end result,
that being your newfound knowledge regarding your printer and profile
accuracy.
Check it out here:
www.colorcheck-online.de/en/report.html
Their English translations aren’t exactly the greatest, sometimes
non-existent but google translate does the job admirably. They provide all
of the required patch targets in a variety of layouts for various
instruments and measurement applications. They have extensive tutorials,
how to section, free downloads of the targets and more. I’m pretty sure
you’ll find the site is exactly what you’re looking for. I’ve been using
their procedures for nearly 10 years and they’re still just as relevant
today as when they were released.
Let me know what you think.
Cheers,
Aaron.
On Fri, 29 Apr 2022 at 11:11 pm, Yves Gauvreau <gauvreauyves@xxxxxxxxx>
wrote:
* Roger, I have no need for "proofing" especially if it means simulating a
CYMK printer on an RGB printer. The patches they suggest we use are created
to be printed on specific papers on a CMYK printer or press, yes I know we
could "proof" that to my RGB printer. Why go through all this work around
instead of going directly to what I want to evaluate, an RGB printer
printing an RGB image on the paper I want as accurately as possible. I want
to know if it prints a black and white as black and white and as neutral as
the inks and the paper can achieve. I want to be able to exploit as much of
the gamut as is possible with my papers. All the papers I used can exceed
both Adobe RGB and sRGB colorspace in some areas and yes the inverse is
true as well. Clipping may be acceptable to some, but I found this
unacceptable and I prefer a more elegant and refined solution. I think
gamut mapping on an image by image basis is the best approach. I think
every one will agree, there is no point to test a printer with values that
were used to create the profile. Furthermore, I would also think there is
no point on using out of gamut values either. Then, what should I use to
make a “good” set of patches, suggestions? *
*Let's say I use the criteria Roger suggest, 1.5 average and maximum 5
DE2000. Would you suggest something specific to evaluate the neutrality and
or the chromaticity independently?*
*Any other* point I should look for?
*/Yves*
Le 4/29/2022 à 8:12 AM, graxx@xxxxxxxxxxxx a écrit :
IDEAlliance recommends DeltaE 2000 with some specific “ideal” numbers.
You could use the same kind of criteria.
For proofing, for instance, the average of the IT8.7/4 1617 patches has to
be within 1.5 and the max was below 5. I sometimes profile my Epson printer
as an RGB output device and when I use IDEAlliance criteria for proofing, I
get the expected values.
Depends what you want to proof.
/ Roger
*From:* argyllcms-bounce@xxxxxxxxxxxxx <argyllcms-bounce@xxxxxxxxxxxxx>
<argyllcms-bounce@xxxxxxxxxxxxx> *On Behalf Of *Yves Gauvreau
*Sent:* April 29, 2022 7:10 AM
*To:* argyllcms@xxxxxxxxxxxxx
*Subject:* [argyllcms] Print evaluation?
Hi,
are there any standards to *evaluate a RGB printer specifically*?
Something like Ideal Alliance certification stuff maybe or whatever but for
an RGB printer.
~Yves