Developing found films is not so different from doing it with the current ones but you need to pay more attention to the details to better set up the process and not run into fatal errors. Fundamental is to try to understand what kind of film you have in your hands, especially if white black or color and whether positive or negative: this will definitely affect the steps to take.
Black & White Films
If the film is BW, there are generally no particular problems in the process even with modern chemical products; However, Rodinal exists at least since it was produced the oldest film roll that you can find and proves to be always a prosecutable solution, especially in 1 + 100 dilution and stand shaking; If you search on the net old technical manuals or film information sheets it won’t be difficult to find the time for processing in Rodinal and from there adapt them to take into account the presumed age of the emulsion with the empirical rule of the increase of the development time about 10-15% for every decade of age.
Alternatively, when the film you have in your hands is an old Ilford emulsion, good results are also obtained with X-Tol in stock dilution, which allows you to reduce the grain compared to Rodinal: keeping good the need to increase the times in accordance with the ” “Seniority” of the film a good starting point with X-Tol are the following times:
- HP3 and HP4:7.5 min
- FP3 and FP4:6.5 min
However, one must take into account a problem related to the time elapsed from the shoot: the progressive veiling (fogging) of the film which leads in time to the reduction of contrast and detail; To overcome this, it is often recommended to use a small amount of benzotriazole to add to the development bath. The simplest alternative, that I follow since a couple of years, is to develop films, whatever they are, in a HC-110 in dilution B bath at a temperature of 18 °c for a time of 7.5 min: A good half of the images that will be shown here have been processed with this procedure.
In the case of colour films, there are no particular problems other than those due to the higher deterioration to which these emulsions are subject in respect the black-white ones, provided that they can be developed in the common C41 baths. The only foresight that we recommend is to lower the temperature at 30 °c and adjust times accordingly.
In the case, however, that the film was born for an older development like the C22, the process becomes complicated. The C22 was the process of developing color films in use before the formulation of the current C41; It is a standard procedure that required a strict temperature control (even more than today!) and foresaw ten steps before obtaining the final negative. The chemicals are no longer marketed, although you may still find a powder kit (I have one, but I will never open it, I think) with a bit of luck.
The best way to go in this case, is to try to develop the black and white image trying to limit the intrusiveness of the color mask. It is important to remember that these films are not compatible with any of the C41 chemistry.
The first C22 film that I found in my hands, I developed it in Diafine, obtaining all the images BN but suffering from the consistent color mask (red); So I thought of eliminating it using the bleaching of the C41 and the final result was a separate and negative emulsion completely transparent and bleaching bath to trash!
The incompatibility is, I discovered then, quite well known and leads right to the detachment of the emulsion from the support, or rather to the removal of the silver. But with a second attempt using the fixing of the C41 separated from the bleaching, however, I verified that the result is obtained.
The alternatives I have undertaken to develop these negatives are two:
- Stand development (1 hour at 1 + 100) in Rodinal, at temperature 24 °c
- Development with ID-11 stocks from 9 to 11 minutes at 20 °c
Both options allow you to alleviate the intrusiveness of the color mask and create negatives at least scanable. The development with Rodinal stand produces a negative that you can also print on paper but the image appears flatter compared to the development with ID-11. Potentially, in any case, any BW developer produces an image.
Reversible films and Kodachrome
For the invertible is worth what is said for the colour negatives: no problem if designed for development in E6, complications if instead born to be treated in E4; To date, I never got a chance to find a E4 film.
For the Kodachrome, which were developed with the K14 process, the only alternative that guarantees results is the treatment with black-and-steel (rodinal stand in Primis), since the emulsion is, by its nature, in black&white.