Digital BW, The Print

----- Original Message ----- 
From: "Tyler Boley" <tyler@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Friday, June 06, 2003 11:53 AM
Subject: [Digital BW] Re: OPM in theory (to Martin's q.)


> I feel like the godfather character- I keep trying to get out and they
> keep dragging me back in!

Tyler,

You know where all the bodies are buried and we can let you leave. Not alive
at least. You simply know too much.<G>

(For those who don't know, Tyler has probably been doing quad grayscale
inkjet printing as long or longer than anyone else on the list and is still
printing with his 3000, custom CMYK separation curves and PressReady RIP to
make some of the very finest prints I have ever seen. Totally from the stone
age back about 1998 or earlier. <G>)

(snip earlier)

> For mono printing systems, we may have a master 16 bit gamma 2.2 (for
> example) file. Our output system, whether Piezo, RGB driver after
> curves, ImagePrint, IJC, whatever, is never perfectly linear or
> possibly not appropriate for that given print. So we may have a final
> curve we want to apply to print they way we want today on whatever
> output system we have today. Why would anyone save their file in that
> state? It's device specific. Also, if our work habits are refined, a
> final curve to a high bit file is not very destructive at all. It's
> not an issue.

In theory you are absolutely correct but I think practically data
destruction remains an issue. I know that all adjustments can be made in PS
in 16-bit mode and I have tried working that way. Unfortunately it isn't a
workflow that goes well for me. I do some initial adjustments in 16-bit but
then drop down to 8-bit for all the fine tuning. While I could go back and
apply all my 8-bit adjustments to a 16-bit version of the file the task gets
way too complicated for me and the results don't exactly match.

For instance you have a copy of my print "Side Aisle and Gate." This PS file
has 23 adjustment layers all with different masks. The opacity of many of
those layers was tweaked several times in combination before the print fell
into place for me (or as close as I felt I was going to get it anyways).
Interestingly this pretty much follows how I print in the wet darkroom and
if you look at my printing instructions and charts it is not uncommon to see
10 to 30 different dodging and burning maneuvers with different contrast
filters. I don't recommend or defend this as a good way to print but it
seems to be the way I like to work.

Also I think most people wind up in 8-bit mode for the same reasons they
stick with a "canned" printing software. Ease of use and generally great
results. While adjustments in 8-bit mode do cause data loss it appears you
can lose quite a bit and still get a fine print. Back to the old combed vs.
un-combed histogram discussion.

Anyways my point is that 8-bit image adjustment is widespread and that makes
data loss from poor or over adjustment an issue. So if something like
OPM/IJC increases the margin of error I have working in 8-bit and allows me
to push the data a bit farther before print quality breaks down, I would be
very interested. If it doesn't, then as you say, it is then a matter of ease
or use and convenience which can be a significant factor.

> I'll be willing to bet that, with OPM/IJC and the new Ergosoft option,
> after initial sep curves are developed or canned ones selected, final
> densitometer linearization is an overall correction applied at INPUT
> to the file on the fly. That's exactly the same thing as applying a
> final correction curve, exactly. Any other method of linearization
> would be ridiculously complex and have to alter each and every ink
> channel.
> So, that a file needs some kind of optimization for printing is not a
> plus or minus of any particular product or output system, but more of
> a convenience feature of whether or not it happens on the fly or you
> do it yourself in Photoshop.

Would tweaking the separation curves take things a step further and
genuinely improve output rather than just manipulating the input data as you
explain above?
>
> Black box printing systems-
> Piezo plugin and Pro
> ImagePrint
> Epson driver with RGB cures user can't edit (for experience reasons)
> Maybe some others, I'm not paying much attention at this point
>
> With these, if you have no flat spots, reversals, harsh transitions or
> other major problems, with well made master files a final tweak is not
> a problem. I'd say, for those not interested in delving the depths of
> individual channel control with the new systems, it's no different
> than what an overall linearization is going to do on the fly with
> these new systems. If the correction can be handled by the particular
> percentage points Photoshop offers in a custom grayscale space, you
> can even save it out and apply it when printing on the fly, assuming
> your output system accepts grayscale in.

Your point is well taken. You have certain input data from the scan or
digital capture and the order or manner in which you alter that data from
its initial to final form would seem to be immaterial to the final result.
(Which goes back to the importance of scanning to printing.) Can we be
certain that all paths treat the data in the same manner? Some workflows
such as the RGB separation curves may put much more stress on the integrity
of the file data than some others. Applying the curves to an 8-bit image
file really hashes the histogram which may or may not effect image quality.
Very image dependent.

All in all though the better the monitor and printer profiles you have to
work with the better the results are likely to be, not because one system is
technically better than another but because the way the tools work can have
a great impact on the artistic decisions.

>
> Obviously, new systems have extraordinary features for those who
> choose to work with them and I'm certainly stoked about the
> possibilities. But an output system is not dictating an unwise or
> destructive workflow, it may however make for a much more convenient
> one. Let me know if I'm missing something, please.
> This is worth restating-
> > Of course, as
> > profiles become available for OPM, not only are they canned and
> easy-to-use,
> > the whole thing is free, which is another matter to consider!

I agree! Perfect business model for us end users but the pit fall here is
the same as with the RGB separation methods. We have a nice free open system
but if it was not for the sustained effort of Paul Roark in curve building I
doubt that it would be as popular as it is. Other than yourself, I can't
think of very many other people who contributed to the library of "canned"
curves. If someone does not drive a similar effort with OPM and QuadTone
RIP, I suspect they may not be widely accepted.

Just to touch on a key point again. If a person is printing with as system
of materials, hardware and software, and achieving satisfying results they
should be very reluctant to leave it for the new and untried. The old adage
of, "If it ain't broke, don't fix it." really applies here.

Martin