RE: Sources for wet plate collodion chemicals

Hello:

        It seems that your understanding about the use of sodium
cyanide may be wrong.

        I have written Mr George Berkhofer, who has been making
collodion images longer than anyone around (since the 1950's). He
wrote me back and I quote his email:
        "I have always used sodium cyanide for any wet plate
procedure. Why? Because it's cheaper than the potassium salt!!...
        In so far as color or tone goes, I do not think you will find
any major difference between the two. In fact, you should find none
at all. You are setting loose two molecules in solution, a sodium or
potassium ion with a plus charge and a cyanide molecule with a
negative. The sodium or potassium is going to unite with the bromide
and iodide and dissolve away, leaving the silver in a fine state of
division. Regrettably the cyanide molecule has a strong affinity for
silver, which is why you must remove the plate from the fixer as soon
as possible, let you dissolve and weaken the image."

        Mr Berkhofer has also made this point on the Wet Plate Forum
quite recently, so perhaps you need to re-read the postings.

        As for the other points: adding a few drops of silver
solution to the developer adds density to the image, and may -- or
may not -- add brightness to the image. Adding silver too soon,
however, can also "block up" the silver image, making it hard to
print through if you are making negatives. The use of nitric acid is
helpful when making ambrotypes or ferrotypes, to add a little sparkle
to the silver. It can also produce a white color to the silver.

        Finally, your reference to the Civil War Reenactors site as
"Nuts" is offensive to the many wet plate photographers who use this
site for information on technique and process. Please watch your
name-calling: it seems inappropriate in an otherwise informative
forum.

Christopher Wright/www.visionsinsilver.com

        PS: May I ask if you actually make collodion photographs?
Your emphatic "NOT" in reference to the use of Sodium Cyanide seems
to suggest that you have tried this chemical, and found it from your
experimenting to be not useful. Would you care to share your
experience?

At 8:27 PM -0700 8/25/05, D. Mark Andrews wrote:
>My understanding is that Sodium Cyanide is NOT an option for wet plate
>fixing. Have never taken the time ask WHY, but I've seen this posted several
>times before on the Civil War Nuts wet plate site.
>
>You can brighten your image a bit if you use hypo by adding a drop or two of
>your silver nitrate solution to the shot of developer before flowing it over
>the plate. Also, I've read that you can use a drop of nitric acid in the
>developer yielding similar results.
>
>Mark
>
>-----Original Message-----
>From: Joe Smigiel [mailto:jsmigiel@kvcc.edu]
>Sent: Thursday, August 25, 2005 8:23 AM
>To: alt-photo-process-l@sask.usask.ca
>Subject: Re: Sources for wet plate collodion chemicals
>
>
>>>> cwrigh2@twcny.rr.com 08/25/05 10:41 AM >>>
>...
>Instead of the expensive potassium cyanide (which is also deadly
>poisonous), use the (somewhat) safer and cheaper sodium cyanide.
>
>Christopher,
>
>Is there any difference in the color of the wetplate image if the sodium
>cyanide is used? I've read and observed that sodium thiosulfate gives a
>more neutral-silver color than the potassium cyanide. Does the use of
>sodium cyanide retain the coffee color produced by K cyanide or is it
>more similar to the hypo result?
>
>Joe
Received on Fri Aug 26 10:03:13 2005