Oh D-fine, you're so fine
You're so fine you blow my mind, hey D-fine,
Sorry for that, that was... bad. Oh well, it's one way to start an article about having fun with chemicals. Photographic chemicals, of a bit more obscure kind. This is Diafine, a two bath film developer that I have been using for the past year to develop all of my black and white negatives with. It's a quick and dirty, hassle-free way of developing film. Oh, and your developer has a longer expiration date than a Twinkie. My current batch is about a year old now and the only reason why I have replenished it (with the reserves from the same batch) is to refill the bottles and free up some shelf space. Although, lately I have been thinking about popping the new cans. A couple of films have left my part A quite dark in color. It still works fine, but it made me wonder.
Back to the matter at hand. As I said, this is a two stop bath. You have chemical A and chemical B. First you soak the film in A, let it saturate for three minutes and fill it back in its bottle. Right after that, you pour B into your Patterson tank, let it soak for three minutes again, pour, rinse, fixate rinse and finish. Did you see a mention of working temperature or variable times for film types or anything like that? No, because basically there are none. I have used this out in the field, in winter and summer and with films that this developer isn't designed for. I do try to keep it around room temperature and around the three minutes bathing time, but sometimes 'oops' happens and to be honest, I haven't noticed a difference.
As said, this is a two bath developer. The most important thing to remember regarding this is that you should never mix the two. If part B contaminates part A even in the slightest bit, you can throw it away. Therefore, I have separate funnels for both containers and I make sure to do the two phases apart, even when I have multiple developments running simultaniously.
The thing with Diafine is, it's a non-variable process. That's it's strength most of the time, for example, you can throw different kind of films into your tank. But it also means that you can't push or pull your film or exercise any other creative control during the developing process. It does add a stronger contrast to the images, but that's about as far as it goes. Your ISO is going to be what the box says, and with that, I mean what the Diafine box says. Yes, according to the manufacturer, the box speed of your film isn't necessarily going to be what you will have to shoot. Although, in my experience, it's fine to stick to the ISO speed for most kinds of film instead of what developer box says. The only film that I haven't found the sweet spot for, is Ilford Delta 3200. At 3200 it's too dark, at 2000 it's still a bit 'meh'. Although, when I shot it with a 6x red filter I got an interesting and pleasing contrast out of it. I have also developed Ilford XP2 with it, a C41 color process film. It did its job, but it ain't all that pretty. As it wasn't the plan to develop it with Diafine, I didn't shoot it at the adjusted ISO value. Anyhow, the experimenting will continue and as far as my go-to films are concerned, Delta 400, Kodak T-Max or Tri-X 400, I will stick to the info on the film packaging. You can check the 'Sampling Film' page on this website to see how it worked for me.
If you want to try this for your self... Wel, I got some sad news bubba. It's not the most common type of developer and if you do find it, it will probably be from the U.S. of A. My personal stack comes from an old art institution that I helped clear out after it closed its doors. Luckily I have enough to last me a long, long time. But if you do find some, I can only recommend it as a no-hassle developer.