Wet plate collodion process and silver-bath maintenance
My last post was about my commision in Switzerland. I’ve shot many plates and when I’ve came back I was sunning the bath for a day (bright sunny day), filtering, etc, but I was still not getting that super sharp shining silver on my plates. With usage of silver-nitrate bath, alcohol, ether, iodides, organic particles and other stuff they dissolve in the bath and you can not get them entirely out with barely sunning.
Common practice is that silver-bath is regularly sunned and boiled only once or twice a year. That goes for ambrotypes, that’s positives. Whereas wet plate collodion negative technique reveals all dirty secrets of silverbath (not to mention photographer’s secrets) and if you want to get a good negative frequent boiling is necessary. Major enemy of wet plate negative is excess of iodides in silverbath and the syndrome of that are white dots in negative or black dots in positive. Or to quote Mark Osterman: “free iodides” cause pinholes in collodion images.”
So what I’m trying to say is that I very often boil my silverbath for usage in wet plate negative, but I also fall in love in the quality of ambrotypes that are produced after freshly boiled and cleaned silver-bath.
How is it done? You can find this technique in The NEW Scully & Osterman Collodion Manual. I can explain you how I am doing it, but I must warn you that I’m Slavic origin and not Germanic or even Anglo-Saxon origin, so if you can use an advice about cleanness from a Slav, then you must be pretty desperate…
Add one small table spoon of baking soda in about one liter of AgNO3 solution. At this stage the pH should be about 6-7pH. I must warn you that boiling silver-nitrate with Sodium bicarbonate (baking soda) will look like the end of your wetplate career, but that’s how it should look. To be clear, the silver-nitrate in the picture above looked perfectly clear before boiling, but since I’ve sensitized about 30 plates format 10×12″ (cca. 2.25 square meters) I knew it’s full of iodides, alcohol, ether and dissolved organic matter. Only when I started boiling it with soda all the feces came out…
A friend asked me the other day how to raise pH in silver-bath after you added few drops of nitric acid. This is the best way. On FB a colleague Michael Koerner wrote a comment: “Plus the sodion bicarbonate (NaHCO3) will (when acidified with nitric acid) turn to carbonic acid (H2CO3), which will over a short time turn to water (H2O) and carbon dioxide (CO2) – bubbles away.”
After boiling you need to add water, filter it, sunn it, filter it, measure gravity of AgNO3, add nitric acid so the pH is back to 4 and you’re finished! Your silver-nitrate bath is reseted. You must know that silverbath like that will be more aggressive then your usual silver-bath, so it’s good to shorten sensibilisation time. I shortened to 2:15 minutes at room temperature. Mark Osterman is highlighting that sensibilization process is judged visually and not measured by time. I think I know what he means, but I need to confirm with him that I truly understand this part of the process, next time when I will see the master. I’m planning to join his workshop of Carbon Printing in Rochester in November. So exciting!
To sum up. I love to reset my silverbath, because then I’m getting best results. Boiling does take toll. I loose about 13.722% of my silverbath solution due to filtering. After boiling I filter the solution about 4 times through double coffee filters. Personally I find it worth the effort, but in wetplate process everyone have their own way of doing things and I’m not saying this method is better than any other. It works for me and that’s the true beauty of this hand-made images. You do it your own way! Ha!
PS: I’ve changed the title of this blog. Before it was Photography Down the Rabbit Hole, but the title Topshit Photography blog is way better. Topshit happens!
PPS: TOmorrow I’m going back to Switzerland to do some more work. Obviously they think the work that I’ve done is worth the money, so more work is waiting for me. Topshit happens!
PPPS: Relevant links:
- http://collodion.org/ Scully & Osterman Studio
- http://collodion-art.blogspot.com/2011/07/silver-bath-maintenance.html (Alex Timmermans)
- My first post about boiling and sorting pH of silver-bath LINK