Tannins are present in a wide range of vegetables, and can be found in roots, leaves and fruits, seeds and sap. Giving an astringent flavor, the tannin has the natural function of protecting the plants or fruits of the parasites that can damage them.
In photographic development, the tannin "replaces" the hydroquinone of the developer liquid (when oxidized, the tannins become quinones).
Although the heating process can destroy part of the tannin present in the husks / leaves / roots, vegetables / fruits, this is the process that I have used to obtain it in a working liquid, given its hydrosolubility.
Developing whit ears corn-
The idea is not mine, originally, I found it in the research I do on alternative revelation: ascorbatedevelopers.blogspot.pt names "Maizol" to a revelation made by him with the ear of corn, crushed, boiling 30 minutes, which associates sodium carbonate, and vitamin C and reveal for 45 minutes at 20 degrees.
Ascorbato gave me the idea, but I preferred to follow the course of my experiences: I have 3 ears of corn, complete with leaves, beards, corn (weighing in total 400 grams). They have been decorating my kitchen for 3 years. The corn is red and of course dry. I choose to pour this whole set, without spoiling, in a pan of water (2 liters) in boiling. I leave 10 minutes and remove the ears (which I dry and hang on the spot where they were).
The next day I take 1 liter of this liquid (Ph less than 6.2, alkalinity of 40) and add the already frequent 50gr of sodium carbonate. I dissolve, I wait 5 minutes. I add 8gr of Vitamin (ascorbate used 15gr ), also as always. I wait 5 minutes, I let the solution stabilize. The temperature, as always, increases by 1 to 2 degrees. This time, unlike all the other products I have ever used, the liquid does not turn black and smelly, but in a red-greenish-brownish tone, I would say that it is oily, in appearance. And a smell less fetid than the "usual."
This photograph was made with my Pentax spotmatic spII, Kodak Tx400 film. I developed at 20 ° for 40 minutes, shaking in the first minute and then 10 shaking for every 3 minutes. I got negatives that were very poorly contrasted, but without any veils. I scanned with an EpsonV500 as a color negative.
In November of 2013 I tried the experience of making a second roll with the same solution of homamade developer whit ears of corn.
F4
Agfapan 100
Negative scan (Epson V500)
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