Interesting Collodion Talk

As I’m in the process of trying different collodion & developer formulas I had the pleasure to have a virtual chat with Mark Osterman. I learned some great insights which will help me control the process on a more sophisticated level. I wish to share these with you.

First of all: Remember that the solvents in collodion affect:

1. How deep the silver goes into the collodion film
2. How strong and contractile the collodion film
3. How long the collodion film remains wet
4. How long the silver bath remains strong and free from contamination
The more ether…the quicker the film dries, the tougher the film (but can cause shrinking) and is less harmful to your bath. Will hold enough silver for negatives or positives.
The more alcohol the longer the film stays wet, more fragile the film, the more it contaminates your bath and the more apt to contain water, which makes crepe lines in your images. Will hold more silver, which is better for negatives…but does not help when making positives which are very delicate images that don’t need density.
When working in warmer conditions (over 20 degrees celcius) the chemistry will respond differently. More alcohol may be added to the collodion to keep it from drying out too fast. The developer also has to be adjusted. The activity of the developer and probable fogging may be reduced in several manners: add more water to the developer, less ferrous sulfate, more acetic acid, or use an organic restrainer such as sugar in the formula.

Anyway, I’ve still got a lot to learn. Hope that my chemicals will arrive shortly and I can start experimenting some more. Simply trying out different formulas will not cut it I’m afraid seeing that the collodion, developer and silver bath used really are very related to each other, as well as the circumstances that have their own set of influences on the result, but I hope this will give me more insight into the process itself.

The discussions I’m having right now are most interesting, so it’s already been worth the trouble! Thank you all!

P.s. I sometimes wish the Matrix would be real. I’d plug myself into “knowledgable” people and suck up all there is to know! At the same time it would make knowledge pretty worthless but still…


  1. Hi Indra,

    After a lot of work, and discussions with Osterman, I have come to the conclusion that the collodion formula is the least important part of the process. If you get the exposure correct, and the developer right its hard to go wrong.


    1. Hi Dave,

      Thanks for your insight!
      This survey will give me a better insight in the process, also to learn how to adapt the developer to different circumstances.

      I saw this guy on Facebook comparing different versions of collodion and the 3-salt version he used seemed having a wider spectral sensitivity and a higher speed than the others (don’t remember by heart which version). So, thought it would be interesting testing for myself. Once I get this over with and have chosen a collodion formula to work with I’ll focus on refining exposure and development to make the most of it.


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