Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Martin Wesley" 
<mwesley250@e...> wrote:
> > -----Original Message-----
> > From: Roy Harrington [mailto:roy@h...]
> > Sent: Monday, August 25, 2003 1:36 PM
> > To: DigitalBlackandWhiteThePrint@yahoogroups.com
> > Subject: Re: [Digital BW] Septone system
> >
> 
> Roy,
> 
> You may recall the 7600 samples of the Septones I showed you at the SF
> meeting. The hue of the prints looked very good but some of the PixelPicasso
> wedges were only okay but not as good as others varying with how the inks
> were blended by the software. The 2200 wedges they sent me are actually much
> better but not all are as smooth as I would like to see.

Yes, I remember the prints.  The hues changes were kind of extreme so that it
was obvious to see.   But the more I think about this septone idea the more
skeptical I become.  I think Shilesh also hit upon the issue -- warm/cool is
only one dimension of the color variations you might want.   I like to think of
it like the LAB space.  B gives you the yellow/blue or warm/cool dimension but
A which is red/green is equally as important.  This gives you the magenta or
eggplant hues that careful selenium toning can give in a silver print.  I think
this is the effect I most miss.  I've always disliked the olive-like tone of some
silver papers and selenium toning solved that.  Likewise I think many of the
carbon inks give me that olive look sometimes and warm/cool doesn't fix it.

> 
> As far as permanence we really need some comparative testing and I nope that
> Paul can assist as his comparative testing of two or three ink sets in one
> trial are the most useful. I have to give Sundance/R9 credit for actually
> printing some of the results of their RIT testing. Only a side-by-side test
> will suffice but I am hoping they are comparable to the PiezoTones or MIS FS
> inks since they were developed in the same time frame.
> 
> Interestingly as far as I know none of the companies we talk about here
> actually make any ink. They are all buying ink from unnamed manufacturers
> blended to their specifications. I have to wonder if some of them are not
> getting the ink from the same place.

Probably so.

> >
> > >
> > > I also wonder if Roy could not add this ability to QuadTone
> > RIP. You would
> > > just need more curves that only effected narrow tonal ranges.
> >
> > The current blending is pretty basic -- just one blend percentage.  But
> > adding one or two more and sliding the percentage wouldn't be too
> > difficult.  The ultimate would be to allow a curve that would
> > allow any mix.
> > This would ensure smooth transitions of tonal changes.
> 
> Do you think that coming up with curve sets that varied two sets of gray 3
> gray inks over highs, mids and lows could be handled by QuadTone? 

I think there's a risk of making things too complicated, but sure if you can
mathematically describe it, it can be programmed.  I might be inclined to
put it into the curve generation phase instead of run time driver phase.

   Or say a
> VM set with 3 toners over three ranges?

The mind starts to boggle with the possibilities.  My inclination, if you want
maximum flexibility, would be a set of 3 or 4 grays that are the purest, no
color pigment set.  Then maybe 2 or 3 toners whose colors are specifically
a "desirable" color like sepia or eggplant.  You would design curves that
used only small amounts of these tones to vary the gray output.  You 
could use generic CMY for the toners but it might be trickier to balance
two different toners.  Who knows?  I'm starting to think I may have to
get a 2200 for ink experimentation.

> 
> Martin
> http://www.borderless-photos.de/guests.html

Roy
www.harrington.com