RE: palladium drydown and developer

This is the "drydown" that I was referring to Chris. The other effect I have
always though more as dull down. While many here seem to connect the two,
drydown as taken from the silver gelatin days, was to me, the wet print
looking lighter. I don't recall reading, or seeing discussion about the
dulling of the print surface. With platinum/palladium printing unlike silver
printing, uncleared ferric can confuse the eye into seeing density where
none will remain. And as with prints that will later be toned with selenium
in the silver world, pt/pd prints that will later be sprayed or treated
should be printed with those future steps in mind; even steps such as the
addition of optical brighteners.

I don't think that you can only attribute drydown to paper shrinkage either.
The thin papers such as Bien Fang have a extreme "dry down" but the paper is
not getting that much smaller. I relate it more to the opacity of the paper
when dry and wet.

Eric

Eric Neilsen Photography
4101 Commerce Street, Suite 9
Dallas, TX 75226
214-827-8301
http://ericneilsenphotography.com
 
Skype : ejprinter

> -----Original Message-----
> From: Ryuji Suzuki [mailto:rs@silvergrain.org]
> Sent: Friday, July 21, 2006 12:35 PM
> To: alt-photo-process-l@usask.ca
> Subject: RE: palladium drydown and developer
>
> For silver-gelatin prints, I use subtraction of exposure. For
> example,
> if I get perfect test strip at exposure time of t seconds, I
> use 0.9t
> seconds for the final prints. If the final print is to be toned
> in
> polysulfide or polysulfide plus selenium, I may further cut the
> exposure
> time, as these toners can darken the image a day after drying
> the print.
>
> The factor above (0.9) is not far from what's used in reality,
> but some
> paper requires smaller factor than others.
>
> Also, using a dim viewing light in darkroom is important to
> prevent
> prints that look too dark in real life situation.
>
> Ryuji
>
>
>
> On Fri, 21 Jul 2006 08:11:38 -0300, "BOB KISS"
> <bobkiss@caribsurf.com>
> said:
> > Hi all,
> > It seems that there are some techniques for minimizing dry
> down and the
> > discussion of the causes is very interesting but I feel, if
> you've got
> > it,
> > how do you live with it? Though I appreciate the commercial
> lab's
> > techniques, I use a microwave oven (which I learned reading
> Ansel in the
> > 80s). Used, they are pretty cheap and work very well for
> drying test
> > strips. I lay the strip across the print in such a way to
> include the
> > important highlight, midtone and shadow, when possible. I
> carry it
> > through
> > the process to about half way through the clearing, give it a
> 5 minute
> > wash
> > and then microwave it for two or three minutes in one minute
> steps,
> > depending on the size of the strip. Voila! A dried down
> print. I judge
> > my
> > densities and choose my exposure accordingly. This has
> proved to be
> > VERY
> > reliable and I hardly ever have a print that isn't the
> density I have
> > chosen. Whether I have chosen well is another question ;-))
> but I get
> > what
> > I asked for!
> > I mentioned in a post about 1 1/2 to two years ago that I
> found that prints
> > from digital negatives had a curious drying phenomenon that
> prints from
> > camera original negs did not. In prints from digital negs,
> the shadows
> > lost
> > density but so did the highlights...they both got lighter!!!
> In prints
> > from
> > camera original negs the dry down was more standard, i.e. the
> highlights
> > got
> > darker and the shadows lighter.
> > CHEERS!
> > BOB
> >
> > Please check my website: http://www.bobkiss.com/
> >
> > "Live as if you are going to die tomorrow. Learn as if you
> are going to
> > live forever". Mahatma Gandhi
> >
> > -----Original Message-----
> > From: Loris Medici [mailto:mail@loris.medici.name]
> > Sent: Friday, July 21, 2006 7:48 AM
> > To: alt-photo-process-l@usask.ca
> > Subject: RE: palladium drydown and developer
> >
> > Hi Clay,
> >
> > My take / understanding is: when you coat the paper with some
> kind of
> > reflective medium (gelatine, gum, wax and polyurethane wood
> finish as I
> > do),
> > the reason of the darkening and contrast increse in the
> shadows is caused
> > by
> > the fact that the higher refractive index of the coat causes
> some of the
> > refracting light stay in the layer... Think of the mirror
> effect water
> > causes when the light hits it surface from beneath with
> angles lower than
> > xx
> > (was it 38? - don't remember exactly - whatever you
> understand what I
> > mean).
> > Since less light is reflected back (and kept in the coating),
> density
> > increases.
> >
> > Maybe your theory with fibers is also effective in this
> phenomenon but I
> > think the actual/main reason/cause of the dmax increase is
> what I
> > describe
> > above.
> >
> > Regards,
> > Loris.
> >
> > -----Original Message-----
> > From: Clay [mailto:wcharmon@wt.net]
> > Sent: 21 Temmuz 2006 Cuma 13:51
> > To: alt-photo-process-l@usask.ca
> > Subject: Re: palladium drydown and developer
> >
> > ...
> >
> > The other phenomenon that has not been mentioned is the
> microscopic
> > 'fuzzing' of the paper surface that occurs as paper dries.
> This seems to
> > affect the dark shadow areas much more. It is really more
> accurately
> > called
> > 'dry-up'. If you slap a wet pt/pd print on a reflection
> densitometer, you
> > will get a much higher reading (in the
> > 1.8 range) than you will a few hours later after it has
> dried. The tiny
> > fibers of the paper then stand proud and cause a loss of
> reflection
> > density
> > that in the best of cases will give you reflection densities
> in the
> > neighborhood of 1.4-1.5. This is almost a full stop of
> reflection density
> > loss.
> >
> > As to what can be done to mitigate this effect, I have found
> that very
> > light
> > gelatin sizing (in the 1% range) can help to a degree.
> > Another approach is to deal with this after the print is dry
> and apply
> > either wax or subsequent gum coats. I have a waxed vellum
> print that has
> > measured Dmax of 1.9 using several layers of Gamblin cold wax
> medium.
> >
> > My personal preference is for additional layers of expose
> gum, since it
> > offers so many options for color manipulation of the image.
> > Finally, a coat of Liquitex Gloss medium diluted 1:8 will
> also have the
> > effect of causing a measurable (though relatively minor half
> > stop) increase in Dmax. Again, I think this is because it
> causes the
> > microscopic fibers to lay down and behave.
> >
> > ...
> >
Received on 07/21/06-12:29:09 PM Z