From: Sandy King (sanking@clemson.edu)
Date: 05/20/03-07:22:24 AM Z
Jacques,
I discuss contrast control in the article.
"Contrast can be controlled by the addition to the developer of a few
ml of a 5% potassium dichromate solution. The practical limit ranges
from as little as 1 ml per liter of developer up to about 16 ml per
liter. This allows the use of negatives from a DR as low as about 1.2
to a maximum of about 2.2. If too much dichromate is added, printing
times will increase considerably and the image will take on a
granular look."
Sandy
>Sandy,
>Great article, but how do I control the contrast? Dicromate in the sensitizer?
>Jacques
>
>Linas Kudzma escreveu:
>
>>Sandy,
>>I just read your Kallitype article on unblinkingeye.com. Excellent!
>>I???ve experimented with the procedure you posted here a while back
>>with some success.
>>
>>During my trials I used a different clearing method (my Pd/Pt
>>development/clearing method) resulting in some variation from what
>>you describe. Basically, what I do is develop for about 30-45
>>seconds, decant(and save)the developer and then clear with one or
>>two changes of a hot (120F) solution of citric acid (approx 5 gm
>>citric in about 1 liter) for about 5 min. My reasoning is that any
>>longer in the developer (potassium oxalate for Pd/Pt, sodium
>>citrate for Kallitype) does not contribute to the image formation,
>>rather only undesirably clears iron into the developer, which I
>>intend to reuse. So I change from developer to the clearing bath
>>earlier. My hot citric acid clearing bath works great for normal
>>Pd/Pt. However, with Kallitype this hot clearing bath turns the
>>Kallitype image bright yellow. Subsequent Pd or Pt toning by your
>>method turns this yellow back to a strong dark image, which while
>>beautiful in it???s own way, is subtly less sharp than my Pd/
>>Pt prints. Even if the color is identical, I can distinguish these
>>Kallitypes from my Pd/Pt prints. This was on Crane's 90# Cover or
>>Stonehenge.
>>
>>I suspect my hot citric acid bleaching and subsequent toning is the
>>difference. Anyone else see such a yellow image after clearing? By
>>yellow, I mean bright yellow, not light brown.
>>
>>Linas
>>
>>
>>Linas Kudzma
>><mailto:lkudzma@earthlink.net>lkudzma@earthlink.net
>>
>>
>>
>>Re: Gold toners and Kallitype
>>Cor,
>>
>>
>>The kallitype article is now up on Unblinking Eye. The direct link
>>to the article is
>><http://unblinkingeye.com/Articles/Kallitype/kallitype.html>http://unblinkingeye.com/Articles/Kallitype/kallitype.html
>>
>>There is another gold toning formula in the article that has
>>slightly different working characteristics than the one based on
>>citric acid.
>>
>>Perhaps someone else can comment on Reilly's remarks about acidic
>>gold toners. I am aware of a need to print slightly deeper when
>>using gold toner than when using platinum or palladium toners. As
>>I note in the article, with gold toners "image contrast is
>>increased by about a step through loss of density in the high
>>values, but Dmax values (shadows) are changed little if at all."
>>With one recent image I needed an exposure of 250 units with a
>>gold-toned print to get the same final density as 230 with a
>>palladium-toned print.
>>
>>However, even with the acidic gold toner the maximum density of the
>>gold-toned kallitypes I have made is as high as those toned with
>>palladium and platinum toning. On Stonehenge paper the reflective
>>reading of both is around 1.52. Those who print on art papers such
>>as Stonehenge with either kallitype or Pt/Pd will recognize that
>>this is a very high maximum density and about the maximum
>>achievable with either process.
>>
>>Sandy
>>
>>
>>
>>
>>
>>>To Sandy and everybody else who wants to contribute,
>>>
>>>I have been printing Kallitypes lately, following the procedure as Sandy
>>>King had nicely wrote down and distributed to the list. The results are very
>>>nice.
>>>
>>>When you use a gold toner before the fix, the colour of the final print is
>>>determined by the gold toner, not by the developer, Sandy told me. This
>>>makes ofcourse sense.
>>>
>>>But there are quite bunch of different gold tonere formula's around, so I
>>>was wondering if these different formula's give different colours in the
>>>end?
>>>
>>>And related: Sandy uses an acid Gold toner (citric acid), but according to
>>>Reilly (The salted paper and albumen print book, or something similar as
>>>title), warns against using acidic gold toners, they are supposed to result
>>>in a weaker image (by heart; an acidic goldtoner replaces an silver atom
>>>1:1, a basic one 1 silver for 3 gold)?
>>>
>>>thanks & best,
>>>
>>>Cor
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