Re: gum negatives redux
Loris,
Using half the dichromate would
increase contrast, correct?
And you use 1.5-2x the
highlight exposure?
Thanks...
Paul
----- Original Message -----
From: "Loris Medici" <mail@loris.medici.name>
Sent: Sunday, September 13, 2009 10:24
PM
Subject: RE: gum negatives redux > > Was your coating solution for shadows very dark / heavily pigmented? If yes > it could be that you need a longer exposure indeed; since as I know it > pigment amnt. will affect exposure time and contrast of the emulsion, so, > what you're experience here is in line with gum principles and expected. But > if only you've a rather extreme coating solution there... > > BTW, FWIW, I usually use half the dichromate and 1.5-2x the exposure when > exposing for shadows. Works better for me... > > Regards, > Loris. > > ________________________________ > > From: Jim Larimer [mailto:jrlarimer@gmail.com] > Sent: Monday, September 14, 2009 7:20 AM > To: alt-photo-process-l@usask.ca > Subject: Re: gum negatives redux > > > Paul, my scientific answer is: Hmmmm? That usually works just fine, but > then, last night I tried the same approach with the same results that you > experienced! It may be that there is surfacing another variable in gum > printing, bringing the number to 1243. Sorry, I have no answer, just egg on > my face ;( > Jim > > > On Sun, Sep 13, 2009 at 5:24 PM, Paul Viapiano <viapiano@pacbell.net> wrote: > > > Katharine & Jim... > > I tried the ivory black at 1 gram / 2 ml gum in a 1:1 ratio with the > pot dichromate. > Exposed for approx half my highlight exposure, but at 25 min in > development, there was hardly any black pigment left on the print. > I need to step-tablet this negative and try a few different > pigments...but... > When doing an exposure for the shadows, would you expect a much > shorter dev time? > > Paul >
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