Developing A Mystery – How to process Unknown Films
When it comes to developing black & white films these days, we have a wealth of knowledge at our fingertips, mainly thanks to the thousands of dedicated photographers on the Internet that are happy to share everything they’ve discovered on photo-sharing sites like Flickr, Facebook Groups, and of course the big developing database sites. Massive Dev Chart, Darkroom Solutions, FlimDev.org and many more. Plus, a tonne of datasheets from films old and new was uploaded by manufacturers and owners of these documents. Yet, there are still times when you either don’t know what film you’re working with, especially with an unknown and unlabeled bulk loader. There are also times when the film is so old that the datasheets are lost in the mists of time. Or there are only a limited number of developing combinations available. Thankfully over the course of nearly a decade of home processing and plenty of reading, listening and learning, I’ve come up with three different strategies that will stop building that mystery and instead develop the mystery.
One Size Fits All – Stand Development
One of the simplest ways to develop any black & white film without going with a monobath developer is to use a highly dilute mix of either Rodinal or HC-110 and then let it sit with minimal or no agitation over a long period of time. And when it comes to unknown films, as it is completely unknown, it might be the best bet to get at least some information from the film itself. One of the best-known methods for stand development is using Rodinal (Any flavour). Mix up a dilution of 1+100 (5mL of concentrate to 495mL of water) or 1+200 (2.5mL of concentrate to 497.5mL of water). Then let it sit for an hour for the 1+100 dilution or two hours for the 1+200 dilution. While many are happy to let it sit alone, I will always give it a 1-minute constant agitation at the beginning then two gentle agitations at the 30-minute mark. In full disclosure, I have never used the two-hour method. While you need to have a bit of an idea of how to shoot the film first, film speed-wise, but if you’re within 1-2 stops of box speed, stand-developing will give decent results. Below is an example of a test roll that came from a partly full bulk loader. I shot the film at ASA-100 after hearing that the seller was ‘pretty sure’ it was Agfa APX 100. It ended up being Ilford HP5+, so even with a two-stop over-exposure and stand-developing, I got low-contrast but usable results.
The second method of stand-developing that I have used is using Kodak HC-110 or Ilford Ilfotec HC. Now, like many of the ways I use HC-110, this method is not an official use of the developer. Known as Dilution J as in The Joker is Wild and after the username of the Flickr user that presented the method online. Like Rodinal, you’re working with a highly diluted mixture of either the older syrup or new formula. Mixing to a dilution of 1+150 (that’s 7mL of concentrate to 493mL of water), you will have to make sure you have enough volume to have at least 5mL of concentrate as HC-110/Ilfotec HC does not like any less. Then give your film an initial agitation of one minute, then let it stand for an additional forty-four minutes with a couple of gentle agitations at the mid-way point. While I’m not fond of the results as much as the Rodinal method, it has helped me out of a jam a couple of times when an HC-110/Ilfotec HC time is not listed on the chart(s). Below are examples of Silberra Pan 100 that I developed using this method.
Six is the Magic Number
If you’re like me, you don’t appreciate long development times. Honestly, I think I start to cap out with regular development at the fifteen-minute mark, especially if I constantly bounce back to agitate the film at the top of the minute. If you’re a long time listener to the Film Photography Podcast or a reader of Mike Eckman’s excellent website, you’ll realize that to them; six minutes is the magic number. The first developer that tends to yield results nearly 85-90% of the time is Kodak D-76 or Ilford ID-11. The saying goes that if you develop your film in a stock dilution of D-76, you’ll end up with good results and be able to refine your development from there.
The second developer that this seems to work with is again Kodak HC-110/Ilford Ilfotec HC; you can get good results and refine from there, developing for six minutes in Dilution B or 1+31. In both of these cases, I often don’t use this method because I tend to use an educated guess, which I will go into in more detail in the next section. But in a pinch, these will at least be able to show you the rebate markings to get a better idea of the film stock you are working with. The examples above are provided by the kind permission of Mike Eckman, who used the six-minute method with a roll of Versapan and ended up adding an extra thirty seconds to the time to get better results. When working with this method, one thing to say is to adjust in small increments if you have the film stock to spare. Generally, I’ll exam the negatives and, based on eye inspection, adjust in either one minute or thirty-second increments (plus or minus).
An Educated Guess
While the previous two methods are good when you have little to no knowledge of the film, this final method relies on having developed many films and records your information and having some idea of the film stock and a handful of times. This is my preferred method when developing films that have a limited set of developing times. I recently worked with Rollei Paul & Reinhold, a special edition ASA-640 black & white film. Sadly the developing chart that was released only had a limited number of times on it and lacked Kodak HC-110/Ilfotec HC times along with Adox FX-39 II. And here is where you’re recording keeping comes into play. Take a look at the D-76/ID-11 (stock dilution) times, then go back in your records and find a similar film with a close film speed (+/- one-stop) that has the same stock times for D-76/ID-11. Then shoot the film at box speed and develop using the times of that film. So, in this case with Paul & Reinhold, the film shares the same times with Bergger Pancro 400. So from there, I used the HC-110 Dilution B times and Adox FX-39II (1+9) times and got some superb results with HC-110 on my first try. You can see these results in the gallery below. I found the FX-39 developed shots a little undercooked. But with my second roll I went with shooting the film at ASA-320 and reducing the developing times. These second results are far better than the first ones through the developer. That only goes to show that while I prefer the educated guess method it still isn’t perfect but gives me a good baseline to work from.
Like any of these methods, you won’t always get a 100% hit rate. Usually, you’ll get good and usable results 80-90% of the time. The important part is that each time you develop a film, you’ll get an additional clue to what the actual film stock is, and from there, it’s easier to find information online or in your own records. It also bears mentioning that if you use bulk loaders, you label the loader and keep it updated so that you don’t forget or pass that onto someone else. In the same vein, when you do get results, especially from obscure or limited combination films, you share your results online with your methods, dilutions, and times so that the next person looking for something will have your work to build on. They might be able to land on a better time or dilution.
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