[alt-photo] Re: Collodion POP/ Collodio-Chloride/ Collodion Aristotype Paper - Instructions, Books, Resources?
fdfragomeni at gmail.com
Thu May 31 13:40:06 GMT 2012
Thanks for the thoughts on toning. I'll use those baselines as I'm working
with it and getting a feel.
As to the Strontium, it does seem that the choice of that particular
chloride was for the effect of color. Pretty much everyone I've spoken to
with any insight into the process and historical formula have echoed that
but I haven't heard back from Mark yet on the topic. Collodio-Chloride is
already established to be so beautiful that I probably won't mess with the
formula at this point. If Strontium Chloride were more difficult to get a
hold of or expensive then maybe it would be work experimenting with
substitutes, specifically Sodium Chloride, but seeing as it is available
and cheap I just wont worry about it.
As for substituting collodion for gelatin in an developing out formula, you
make a really good point that I'd overlooked. The role of the physical
characteristics of gelatin that play into controlling the growth of silver
halide when the gelatin is sensitized. Surely collodion won't behave in the
same way and while it may be possible to do it probably won't be as simple
as just plugging in collodion and changing nothing else. It is with that
that I probably will just bypass experimenting with the substitute until I
have the time to play around. Collodion would have been a bit easier for me
to work with but I think I can make gelatin work.
Thanks for your help with this!
On Thu, May 31, 2012 at 6:12 AM, Clarence Rhymer <crhymer at northwestel.net>wrote:
> Hello Francesco,
> I have toned my prints in Gold/Borax, Gold/Bicarbonate and Gold/Ammonium
> Thiocyanate. Yes, Gold is expensive, but one doesn't use all that much per
> print. IIRC the Thiocyanate was more black/neutral, but that was not my
> goal, so I can't say for sure. Remember, like wet-plate, these processes
> are done almost completely by inspection. It is a lot like "cooking with
> your mother". One adjusts the process until it looks right. You should
> tone for between 2-10 minutes. Any faster (more aggressive toner) and it
> does not tone well. If it takes more than 10 minutes you need to
> replenish. Since in POP one exposes by inspection and tones by inspection
> the results are rarely the same twice, but with experience one can achieve
> the desired result for that negative.
> As to which chloride to use (calcium, lithium, strontium, etc.) I believe
> it was claimed in the old literature that they resulted in different
> coloured prints. I don't recall seeing Sodium Chloride used. Mark would be
> able to give you a quick answer to that one. Strontium Chloride is easily
> available and not expensive, so I have never tried anything else. I have
> used both Sodium and Ammonium Chloride for albumen prints.
> As to substituting Collodion for Gelatin in an developing out formula, I
> would be surprised if this were achievable by plugging it into the formula.
> The former is made in Ether/Ethanol the latter in water. It is the
> controlled growth of the Silver Halide crystal in gelatin that gives the
> possibility of a developing out product that is exposed dry. Having said
> that, there were collodion dry-plates produced for a time and even colour
> sensitized collodion plates (bromide IIRC) used until the early part of the
> 20th century.
> On 30/05/2012 12:05 PM, Francesco Fragomeni wrote:
>> One more question, do you tone your Collodio-Chloride POP prints? If I
>> tone, I imagine I'd tone in a Gold Chloride/ Sodium Thiocyanate toner as
>> was common in it's day. Toning is something that I haven't read much about
>> in specific reference to Collodio-Chloride POP. I've just read that it
>> the same toning procedures as Albumen. I would like as black and neutral
>> a tone as I can achieve. Most of the examples of Collodio-Chloride that
>> I've seen have that characteristic but I'm unsure if it is the raw
>> process's inherent tonal characteristic or if it is from toning. The
>> book references Thiocyanate toners as most common with Collodion-based
>> formulas. As I understand, Gold-Chloride/ Sodium Thiocyanate toners
>> neutral blacks. If that is the key then the Gold-Chloride is going to be
>> the most expensive component of the whole process.
>> Let me know your thoughts.
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