Photography, Fine Art, Wet Plate Collodion, Alternative photography

Wet Plate Collodion – silver-nitrate bath pH problem resolved!

with 7 comments

Recently I’ve noticed that I have a problem with silver-nitrate bath in my Wet Plate Collodion photography. I’ve done a successful portrait of Neža Peterca for Mladina weekly and then I’ve made another one of Damjan that was assisting me and this thing happened! I know this edge of fog is because of uneven dipping to the silver-nitrate solution, but if this happens only “boiling” bubbles occurs and not this fog! Than I noticed that the fog is also on the Neža’s portrait! And also on other portraits! Oops!

Those small lines are of course caused by AgNO3, but I didn’t thought it’s caused or at least related by a low pH issue!?!

I_knew it’s a pH issue in my silverbath, but I had two or even three litmus papers and each of them was showing different results. I had enough of this and I’ve bought an electronic Ph checker and also a buffer pH4. I calibrated my checker so it was exact on two decimal numbers! No pH will mess around with me, I tell you! The measurement was shocking. My silver-nitrate bath was 2,2pH and it should be pH4!

Who’s cooking today? Daddy is cooking today! What will be for lunch? Concentrated silvernitrate soup, evaporated to 20%. Hm… how come today aren’t any mosquitos flying around? I don’t know…

I’ve read Timmerman’s post on maintinace of AgNO3 bath, so I was going to cook! I evaporated 80% of solution and then I add fresh water, hoping that will fix the pH issue. It was better, but far from the wanted result. My AgNO3 solution was pH 2,8, but it was really clear (after I filter it) and real beauty on which I was resting my eyes! I know it sound weird, but wetplaters we find beauty everywhere.

The issue of pH was still there, although my plates were good for my standards and I never had them so clean 🙂 Check my first picture below. I’ve bought 10 ml of concentrated ammonium in a local drug store and I add only on small drop to 350ml of AgNO3 solution and the effect was immediate, from 2,8 pH to 3,8pH. Then I redid the test and results are published and commented bellow.

16 flash bursts
pH of AgNo3 solution 2,8

16 flash bursts
pH of AgNo3 solution 3,8

8 flash bursts
pH of AgNo3 solution 3,8

4 flash bursts
pH of AgNo3 solution 3,8

Conclusion: The boiling of AgNO3 did dramatically purified this solution. The raise of pH from 2,8pH to 3,8pH made my emulsion more sensitive to light and that’s for about 1,5 step. I’m not sure that those small lines on a plate are also caused by a low pH, but now they are gone! A small step for photography, a giant leap for me 😉 More about my work on

7 Responses

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  1. Fantastic work, I’m in awe….. This is so beautiful, and an impressive craft of art! Love this, thanks for sharing!


    31 August, 2012 at 21:56

  2. Chemistry is an art……… art of discovery………how rewarding and what a sense of achievement…… you know what the first photographers felt……. I am happy for your successes. Brilliant Borut.

    John M Smith

    31 August, 2012 at 23:41

  3. Thx John and Marie! Exactly, how did the first photographers flet like? I feel like I am a lonely rider since in Slovenia I don’t know no one else who would do Wet Plates on a monthly basis, but I have books, internet and a contact with Miša Keskenović, my mentor. Not to mention I didn’t have to make my own cameras and optics, although also that’s on my to-do list 😉

    Borut Peterlin

    1 September, 2012 at 00:33

  4. Oh, you have a mentor, lucky you! I agree, it feels kinda lonely sometimes. I would like to try different processes, just to have tried them.. Maybe just be bitten by a new bug. And I also want to try large format, to see if it is something for me. But I just don’t know where to start…. In Sweden most people just say, film? Oh no!! Nothanks!….
    So, thanks god for internet! 🙂 But I’m really really jealous of you having a mentor….. Congrats!


    1 September, 2012 at 15:55

  5. Good test!
    thanks for the additional info.



    6 November, 2012 at 16:45

  6. […] PPPS: Relevant links: – Scully & Osterman Studio – (Alex Timmermans) – My first post about boiling and sorting pH of silver-bath LINK […]

  7. when was the first image take? what date ? thanks


    20 October, 2013 at 05:32

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