Joseph Arkins (arkins@banet.net)
Wed, 13 Oct 1999 21:55:54 -0400
In my experience with gum, when you coat for the long "highlight" exposure, you
use a good deal less pigment in the gum/pigment/bichromate mix, so the maximum
density is not great anywhere on the image with the printing using that coating
mix. So, effectively, the highlight printing is low contrast and low "d-max",
and therefore optimized to render detail in the highlights without blocking up the
shadows.
Hope this makes some sense. . .
Joe Arkins
NY, NY
Wayde Allen wrote:
> On Mon, 11 Oct 1999, Judy Seigel wrote:
>
> >
> >
> > On Tue, 12 Oct 1999, lawless wrote:
> > >
> > > Gum printing needs a different type of negative, I believe, but others can
> > > tell you about that.
> > >
> >
> >
> > It does & it doesn't. If you want a one-coat gum, then you have to
> > compress -- no more steps in the neg than gum will print at one time (like
> > maybe 6 or 7). But if you plan several coats, you can use any kind of neg
> > you want -- getting more of the range with each coat -- or actually the
> > other way around: start with the whole range in a light color, then print
> > less with each following coat, each a bit darker & shorter range than the
> > one before, finishing with shadow detail.
>
> This has always confused me a bit. I can see printing a negative for the
> shadows (clearest areas in the negative) since those would take the least
> amount of exposure. What bothers me is that the highlights (darkest
> regions in the negative) need the most exposure to print. It has always
> seemed to me that printing the highlights should make the shadows overly
> dark.
>
> I guess that printing the highlights with a lighter pigmented coat
> (or maybe even a thinner coat) would help. Still, I worry about making
> the print too dark this way. How is this prevented?
>
> - Wayde
> (wallen@boulder.nist.gov)
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