Spots, stains, streaks, fogging, ridges all of this happened on my plates. Results were very inconsistent and each session revealed something new.
I won't bore you with all the details, but will just mark, also for myself, a few points important to remember:
- silver bath is the least likely cousing problems. It is good to prepare a proper amount of the bath from previously checked silver nitrate source, get myself a hydrometer and only replenish the silver when needed.
My problems started with the new silver bath mix and I stubbornly suspected it as a main reason of the problems, testing it, measuring pH, etc....
At least I bought myself litmus papers, so now I can be sure my pH is somewhere around 4 to 5 for ambrotypes, (and 6 might be better for negatives) and I've got some baking soda in stock to be able to increase alkalinity.
It's good to sun (expose to sun) the bath from time to time to get rid of contamination.
- developer is very sensitive to temperature and won't work properly above 18 Celsius degrees. Especially in the dark box it is very easy to get the developer to be too warm. It will cause fogging and stains and many different strange things
- overdeveloping the plates (especially in warm weather) will result in a faded image and stains again. If it's impossible to develop the plate within 15 seconds the exposure time should be extended accordingly
- even though in Irish weather the temperatures don't go to extreme, they are high enough to make my collodion drying too quickly, I think I'd need a separate mix for warm days, with bigger amount of ether and alcohol.
- some sort of mobile/tourist fridge is a necessity for work on location
(not only for keeping collodion cool, but developer and plates as well)
I hope that's it for now. Now I'll be moving to 8x10' format and I guess - new challenges :)
I'd like to thank Gwen Wilkinson - 'Irish collodion guru' :), and Tomasz Mielech, my collodion workshop teacher, for help in resolving these problems!!!
Here are some better plates I managed to make in this period :
and here are the examples of plates with stains, :)