intensify collodion negatives

[rariola77]

Hi, Im interested in making collodion negatives. The formula Im going to be using is old workhorse and following Coffers manual will try mild intensification method. problem is i cant get nitric acid. Is there a workaround to this. I was also going to try making a dedicated negative collodion formula but I cant get Ammonium Iodide either. any suggestions is greatly appreciated.

[paulbarden]

Hi, Im interested in making collodion negatives. The formula Im going to be using is old workhorse and following Coffers manual will try mild intensification method. problem is i cant get nitric acid. Is there a workaround to this. I was also going to try making a dedicated negative collodion formula but I cant get Ammonium Iodide either. any suggestions is greatly appreciated.

Brian at UV Photographics.

[rariola77]

thanks paul but Im currently in a third world country and none of those can be shipped here. I could try intensifying without nitric acid. just wondering what the role of nitric acid is and if i can substitute it for something else. coffers dvd is very vague about it and i read thru the manual several times.

[paulbarden]

thanks paul but Im currently in a third world country and none of those can be shipped here. I could try intensifying without nitric acid. just wondering what the role of nitric acid is and if i can substitute it for something else. coffers dvd is very vague about it and i read thru the manual several times.

I don’t think there’s a substitute for the nitric acid for the silver redeveloper component. I’ve used Coffer’s technique and find it simple and easy. Surely there must be someone in your country that can supply you with a few ml of nitric acid? Can you inquire at your nearest high school chemistry department, or university?

[colbysadeghi]

Coffer has developed another intensification technique using iodine. If you’ve already gotten a manual from him I’m sure he’ll let you in on it if you get in touch with him.

[rariola77]

thanks colby. got his manual is 2010. i know he keeps the section on the back updated. ill try and contact him.

[fatherdougal]

Quinn also describes redevelopment in his books (and on youtube).
You can find some info at around 16:40 in this video
https://www.youtube.com/watch?v=vjBdguAZ_gY

There is also some information about replacing pyrogallic acid with ferrous sulfate at around 27:20 if you have a hard time acquiring that locally.

[Petzval Paul]

I don't have the formula handy, but - years ago now - I used the copper intensifier recommended by John in his manual and it worked great. I think that is mostly just a copper bleach followed by silver nitrate, with no hazardous chemicals needed.

[paulbarden]

I don't have the formula handy, but - years ago now - I used the copper intensifier recommended by John in his manual and it worked great. I think that is mostly just a copper bleach followed by silver nitrate, with no hazardous chemicals needed.

The OP is referring to that same technique, and the Silver nitrate bath requires 6 drops of Nitric acid to complete the recipe. (Part A requires both Copper sulfate and Potassium bromide)

PS: if Silver nitrate isn't a "hazardous chemical" then I don't know what is!

[paulbarden]

Quinn also describes redevelopment in his books (and on youtube).
You can find some info at around 16:40 in this video
https://www.youtube.com/watch?v=vjBdguAZ_gY

There is also some information about replacing pyrogallic acid with ferrous sulfate at around 27:20 if you have a hard time acquiring that locally.

And I can guarantee you that Ferrous sulfate works just as well. I determined from my own testing that there was no significant benefit to choosing Pyrogallic acid over Ferrous sulfate.