(Resend, just realized that Thunderbird was replying to individuals, not
the list. Had to set an option...)
Ok, it's been awhile that I've been messing with this. Reporting back
and asking for more input:
My progress to this point:
A. Try understand the problem better and try to get more patches around
the problem area (the sharp corner of the "mouth" of the "cone" colprof
makes from the "spike") so colprof can handle that transition area
better, might have to use -qh also?
I recompiled a custom version of colprof (that was a challenge in itself
on windows...) to replace the little "balls" in the 3D plot with the
name of the patch (e.g. C19) so I could more accurately tell where that
spike was occurring in the patch set. I then tried making a chart that
was just a patch set that just covered that area and after
printing/reading I added the results to the original profile's scan. No
major improvement unfortunately.
B. Try out PrintFab Home L alternate RIP/driver and reprofile
PrintFab prints much differently than the Epson driver (lays down more
CMY in the K), this improved things quite a bit but still needs improvement.
C. Get some matching Cone ink for the other colors (full Cone Color Pro
inkset) that would probably match densities better.
This improved things further, this brings the Epson driver in the
"useable" range now. Printfab looks even better. Cheating a bit by
choosing to use printfab's canned paper profile and on top of that
profiling with Argyll yielded excellent neutrals and great overall
results. Enough for me to make a larger patch set and be somewhat happy
with final print results. Still learning though and I'm realizing the
problem is black point compensation and how it deals with that spike.
Printfab is actually raising the black level L value a bit and thus
brings it in line with CMY a little better (By laying down more CMY at
the low black levels) I would be happy with this but instead of my
shadows being too open now they are a just a bit crushed. I can comp
this manually with some levels/curves in photoshop but the point of a
good profile is not to have to do that... FYI I nearly always print in
Rel Col, it seems to a better job with color and overall balance than
Percep for me. But in this case Percep pulls out the shadow details
better since it's not doing black comp and just scaling it. Still
don't like it though... So on to new territory for me, CMYK printing.
PrintFab has both RGB and CMYK printing options and so far I have used
RGB. I printed and read a CMYK chart and I'm finding that the K by
itself is MUCH darker in L value than CMK (even within the Cone Pro CMY
inkset) so that if any CMY gets added to the K it makes it lighter (Goes
from a maximum K of just under L3 up to L6 instead) So given that most
inksets don't behave that way, my new question is how do I adjust the
black generation curve in Argyll to allow for only K black at the
darkest colors? I'm sorry I'm a complete noob when it comes to color
separations. Is -kx where I want to head? Also seems like I loose a
lot of gamut in CMYK for some reason but there a lot of knobs to tweak
so I'm not sure I have it right yet (I may have turned the driver ink
limit down too far to avoid pooling but killed gamut, need to test...)
Anyway, some help in the black generation department would be "helpful"
Thanks!
-Brandon
-------- Forwarded Message --------
Subject: Re: [argyllcms] Re: RGB Printer profile shadow detail issues
Date: Fri, 8 May 2020 18:47:35 -0700
From: Brandon Bates <brandon@xxxxxxxxxxxxxxxx>
To: Lessbones <lessbones@xxxxxxxxx>
I'm looking at three options to try right now (I'm on PC, but I've
looked into the gutenprint drivers under linux a bit and poked around in
the ESC/P3 protocol manual a bit):
A. Try understand the problem better and try to get more patches around
the problem area (the sharp corner of the "mouth" of the "cone" colprof
makes from the "spike") so colprof can handle that transition area
better, might have to use -qh also?
B. Try out PrintFab Home L alternate RIP/driver and reprofile
C. Get some matching Cone ink for the other colors that would probably
match densities better.
-Brandon
-------- Forwarded Message --------
Subject: Re: [argyllcms] Re: RGB Printer profile shadow detail issues
Date: Thu, 7 May 2020 08:39:31 -0700
From: Brandon Bates <brandon@xxxxxxxxxxxxxxxx>
To: Alexey Gribunin <Gribunin@xxxxxxx>
Interesting, thanks, I saw that spike in the profile viewer on both
profiles, but looking at the ti3 file with the patches makes it a little
clearer. Printer driver settings are the same for both printers with
the exception of "Edge Smoothing" being on for the 1430 (no such option
on the R300) and PhotoRPM instead of Best Photo on the 1430 as well
Otherwise its: No ICM, High Speed, Premium Semi Gloss and that's it..
There's no option for use black ink for text.
So I compared an older profile made with a different ink combination and
I don't get as bad of a spike (still floating above the black point
though, not sure what that means). Also checked the laser printer I had
trouble with - also has a spike (though a little "fatter").
I started with Precision Color PCK3HD inkset, but I wasn't happy with
the black dmax at only L9 or so. So I switched out only the black with
the more expensive but still reasonable Cone HD black which brought it
down to just below L4, which was much better. So obviously something
with my changes to the ink combination are to blame, but I want that
combo. Given that then I assume I need to get some more patches down
there somehow to try to characterize it better? Is there an option to
do that? I've tried targen -V in the past but didn't have much luck
then solving the problem, maybe should try again? Is there another
option I should be looking at? Manually adding some patches?
-Brandon
On 5/8/2020 4:34 PM, Lessbones wrote:
Try using gutenprint drivers— I believe there is one for the 1430, and that should give you full control over the ink limiting, full to dilute transitions, etc. Then you’re not being funneled through Epson’s black box processing which is only meant to be used with their specific inks (from experience, in some models the black ink is greenish, so they’ll automatically add magenta to it to compensate, and there’s no way around it unless you use a different driver. This screws up 3rd party inksets).
Once you get the hang of the gprint driver try argyll again in CMYK mode. Ultimately you should fare better, but it will be a lot of trial and error. Personally I find that fun though :/
On May 8, 2020 at 11:11 AM, <Dmarc-Noreply <mailto:dmarc-noreply@xxxxxxxxxxxxx>> wrote:
I’ve seen articles in the past that also argue for the converse approach, increase the ink density for optimal printing. It is always going to come down to individual choice. I’ve seen a lot of very good fine art printers who use only Adobe Lightroom and usually homemade profiles. This is pretty much my approach and certainly the screen to print match is extremely close and the prints look good in the few office displays I have done over the years. I have only use Argyll for profile creation and have tweaked the workflow for my own needs. As others have also noted, you are at the ‘mercy’ of the printer manufacturer and their driver. I’ve had two Epsons and now a Canon printer and have been satisfied with their performance.
Alan
*From:* argyllcms-bounce@xxxxxxxxxxxxx <argyllcms-bounce@xxxxxxxxxxxxx> *On Behalf Of *edmund ronald
*Sent:* Friday, May 8, 2020 1:27 AM
*To:* argyllcms@xxxxxxxxxxxxx
*Subject:* [argyllcms] Re: RGB Printer profile shadow detail issues
This fairly typical of what one gets with consumer inkjets Whether it's due to black generation or other issues is a different question. One trick to improve matters a bit is to use the driver controls to create less "dense" prints, except of one really feels one needs 300% ink coverage etc.
Matters used to be much worse, but inkjet drivers have a improved a lot over the past ten years.
Edmund
