Digital BW, The Print

----- Original Message -----
From: "Todd Flashner" <tflash@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Wednesday, June 26, 2002 9:12 AM
Subject: Re: [Digital BW] Re: pshop 6->7 VM (converts file differently?)


> on 6/26/02 2:30 AM, Martin Wesley wrote:
>
> > I can see what is happening to the image data with this workflow. I have
no
> > idea what is happening to the data with the Piezo driver or a RIP.
>
>
> Martin,
>
> Your post nicely summarizes the landscape here, and I should probably just
> let it stand, but I have work I'm trying to avoid. ;-)
>
> I think the above gets to the heart of what my quibble was. There seems to
> be an assumption (by many, including myself at one point) that the RGB
> workflow is harsher on a file than sending a grayscale file through the
> Piezo driver/profile, and I'm just not sure that is the case.

Todd,

Can't argue with you on that since I don't have anyway to accurately test
it. Perhaps someone who uses a RIP workflow where you apply CMYK separation
curves prior to printing can comment on what the histogram looks like before
and after. Of course we don't know if the Piezo driver functions in CMYK or
not. Odds are it does partition the inks in some fashion.
>
> Yes, in the RGB workflow we know the image is tortured by radical
separation
> curves, but do we know that the Piezo alternative is any less dramatic?
> Unfortunately we don't. *Something* is still partitioning those same ink
> densities. I'd say the proof is in the output, and we know that both can
> fail.

Yep.
>
> > Posterization can have many sources.
> > The most common is probably over manipulating 8-bit files and I think
the
> > second maybe scanning.
>
> I'll spite myself and go out on a limb and suggest that the inkjet process
> itself is the primary cause of the posterization most on this list
> experience.

Could very well be true. The one caution I have in that regard is that many
people report problems with workflows, materials and equipment identical to
what others report success with. I have seen people get very poor results
with the MIS-VM on a 1280 with Windows identical to my set up. My wedges
look pretty good and theirs looked pretty hopeless for use with real prints.
This is very technical stuff and there would appear to be many variables
that may not always be under control. In the end though I have seen so many
excellent ink jet B&W prints and heard so many stories of failure I have to
conclude that it is a workable medium but not an easy one. I don't consider
silver printing easy either.
>
> My sense is that since all workflows are working with similar ink
densities
> and similarly applying those densities across the image, tones that fall
> into those density (and sometimes hue) cracks and transitions may fail
> similarly with all systems.

I am not sure that the ink densities are that close. From what Paul has said
there is quite a bit of density variation between a Y position Piezo ink and
a Y position MIS-VM ink.

>That all are capable of posterization with
> pristine files seems to bear that out.

Only if the original scans and/or source negs are free of posterization.
From my own experience I have encountered posterization either as a result
of too much image manipulation or a neg that was flat to begin with. A good
test would be to take your pure 8-bit file that posterized and print it as a
mono ink print to see if the posterization is a result of the partitioning
or not.
>
> Now if this were a group of LTV outputters I'd agree fully with what you
say
> above.

Since photo laser printers are RGB devices printing on color material I
guess no partitioning is involved so data loss or damage should not be an
issue. I wish I had one. <G>

Martin