Andreas,
I’m sorry, very sorry in fact, I didn’t read the fine print, sort of speak, as
usual and I got stock on the CMYK stuff, I apologize. There is a huge amount of
info on this site and honestly I wouldn’t know where to start to begin with.
I think I’ll just make some print from 8 bit images and from 16 bit images and
if I can’t see any difference that will be it.
Thanks Andreas and all others,
YG
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Andreas Kraushaar
Sent: Sunday, October 14, 2018 2:07 PM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: testing
you can apply this (in principle) also to RGB and deduce technical and visual
discernible tonal steps
regards
Andy
Wir stellen den Hintergrund in den Vordergrund.
We put the background in the foreground.
—————————————————————————
Dr.-Ing. Andreas Kraushaar
Abt. Vorstufentechnik
Fogra
Forschungsinstitut für Medientechnologien e.V.
Einsteinring 1a
85609 Aschheim b. München
Telefon: +49 89. 431 82 - 335
Telefax: +49 89. 431 82 - 100
E-mail: <mailto:kraushaar@xxxxxxxxx> kraushaar@xxxxxxxxx
Internet: www.fogra.org
-----------------------------------------------------------------
Geschäftsführer: Dr. Eduard Neufeld | Sitz des Vereins: Aschheim b. München |
Vereinsregister 4909
Am 14.10.2018 um 15:04 schrieb Yves Gauvreau <gauvreau-yves@xxxxxxxxxxx>:
Thanks for the reference Andreas, unfortunately I work only with Inkjet
printers and I use only RGB colorspaces.
Some here and elsewhere made me investigate this further with the idea of what
can be discernible or not on a print and since I intend to buy an I1Studio
spectrometer to create and optimize my own profiles. I found out we need
about 2.5 8 bit levels to be able to see a difference, so to some degree that
is much less than I expected a 16 bit file would result in but a 20% increase
is not so bad and obviously good to have on your side.
Thanks again,
YG
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Andreas Kraushaar
Sent: Saturday, October 13, 2018 3:13 PM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: testing
Hi all,
you might check a method we have develop termed „discernible tonal steps“:
<https://www.fogra.org/en/fogra-research/wc-digital-printing/digital-printing-current-projects/imagequality-35003/research-topics/tonal-steps/evaluation-the-number-of-tonal-steps-28cmyk29.html>
https://www.fogra.org/en/fogra-research/wc-digital-printing/digital-printing-current-projects/imagequality-35003/research-topics/tonal-steps/evaluation-the-number-of-tonal-steps-28cmyk29.html
regards
Andy
Wir stellen den Hintergrund in den Vordergrund.
We put the background in the foreground.
—————————————————————————
Dr.-Ing. Andreas Kraushaar
Abt. Vorstufentechnik
Fogra
Forschungsinstitut für Medientechnologien e.V.
Einsteinring 1a
85609 Aschheim b. München
Telefon: +49 89. 431 82 - 335
Telefax: +49 89. 431 82 - 100
<mailto:kraushaar@xxxxxxxxx> E-mail: kraushaar@xxxxxxxxx
Internet: www.fogra.org
-----------------------------------------------------------------
Geschäftsführer: Dr. Eduard Neufeld | Sitz des Vereins: Aschheim b. München |
Vereinsregister 4909
Am 13.10.2018 um 12:19 schrieb Paul Langmead < <mailto:paul@xxxxxxxxxxxxxxxx>
paul@xxxxxxxxxxxxxxxx>:
Hi Yves,
First of all, 16 bit doesn't expand a colour space, it simply adds more colours
in between, which will reduce banding if a gradient between two very similar
colours is present in your image. If print is your goal, then all of this is
rather moot, as even the best paper and ink combinations have small gamuts
compared to most capture devices (the gamut of Fujichrome Provia 100F and the
Hasselblad X1 scanner is astaunding). Furthermore, displays are still only 10
bit, and, as of writing all modern operating systems offer standard support
only for 8-bit video output (MS is dabbling with 10-bit, but it's certainly not
mainstream at this stage - this will change of course).
As I understand it, the benefit to sending 16 bit data to the printer is that
you allow the printer software to convert the data to 8-bit before reaching the
print head rather than Photoshop - the advantage being that the printer
manufacturer probably better understands how to optimise for it's print head
than Adobe. This of course will change (and may have already with newer
equipment), but the weak link is still the paper/ink, which is of course why we
are all here. This is unlikely to improve more than incrementally in the
foreseeable future.
I guess what I'm trying to say is that being particular about your output
profiles is probably more important than worrying about bit depth at the print
head, but I'm hoping Greame will chime in if I'm wrong.
Cheers,
Paul Langmead
__________________________________________________________
Atelier Paul Langmead - Photography and Fine Art Printing
Wilhelminenhofstraße 68a, Berlin 12459
<http://paullangmead.com/> paullangmead.com / +49 (0)17677251462 /
<mailto:paul@xxxxxxxxxxxxxxxx> paul@xxxxxxxxxxxxxxxx
On Sat, 13 Oct 2018 at 11:00, Yves Gauvreau <
<mailto:gauvreau-yves@xxxxxxxxxxx> gauvreau-yves@xxxxxxxxxxx> wrote:
Graeme, Ben and Paul,
I have 2 objectives about this high bit depth printing stuff the first one
is that I have images of nature that present a very wide range of colors
often a more or less important part of them outside sRGB space, I always
shot raw in the hope to capture all of them, I use mostly use Lightroom with
its huge colorspace ProPhoto RGB as workspace again such that I don't clip
anything at birth as someone put it. I've setup Photoshop to use the same
colorspace as LR. I think if I convert voluntary or not such images to 8 bit
depth image I will lose quite a lot of data that may very well produce
prints of less than optimal quality. From the little I know, papers, ink and
printer combo are now capable of producing colors that cover a larger color
space then sRGB often filling a large part of Adobe RGB and even sometimes
they present colors protruding outside of AdobeRGB, so I want to exploit
this as much as possible. As for high bit depth, my thinking is that with
these bigger volume of colors, the distance between to colors should
increase and thus artefact like banding should be worst then with a smaller
distance between colors. Now this should practically be way to minute to
detect even considering noise and other factors if any at higher bit depth,
thus my interest.
A long time ago I came across a guy named Norman Koren at the time he
produced an image to help us adjust our monitor visually to have a specific
gamma, either 1.8 for a Mac and 2.2 for the window OS. I suspect this was
done using advanced knowledge about frequencies and a pretty good
understanding of visual perception.
The reason I'm writing this in the middle of the night for me, is that I
wonder if a similar approach using knowledge about frequencies and visual
perception would make it possible to kind of amplify the signal well above
the noise level to make it easily discernible that this print can only have
been made using a 16 bit printing process or not.
Adobe as a color print utility that I see often mention so that no color
management is use in the printing process for the creation of profiles,
maybe there is a possibility there as well. I've written to Adobe about this
high bit depth printing thing but I didn't mention this utility. They about
convinced me that none of their product such as LR and PS change the mode to
8 bit per channel during the printing process at any time on their side.
Anyone knows a physicist?
Thanks for all your effort,
Yves
-----Original Message-----
From: <mailto:argyllcms-bounce@xxxxxxxxxxxxx> argyllcms-bounce@xxxxxxxxxxxxx
[mailto: ;<mailto:argyllcms-bounce@xxxxxxxxxxxxx> argyllcms-bounce@xxxxxxxxxxxxx]
On Behalf Of Graeme Gill
Sent: Friday, October 12, 2018 7:29 PM
To: <mailto:argyllcms@xxxxxxxxxxxxx> argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: testing
Yves Gauvreau wrote:
Anyone as an idea if it is possible to test, check or verify if a printwas done at a high
bit depth of 16 bit per channel?
