A Question of Timing

Even though I've been developing film for years, I've always had questions as to when to stop the clock regarding film development. For example, I just processed a roll of Ilford Delta 100 in Rodinal 1:50 for 14 minutes (20 celsius). I stop the development clock the moment I pour the chemical OUT of the tank (14 minutes in my example). Other folks tell me that the development clock should stop when you pour IN the stop bath (which means I should pour out the developer at 13' 30" and add the stop bath at the 14 minute mark). I'm curious as to what you folks are doing.

Jim Bielecki

Unless you are working with a very short development time I do not believe it matters which practice you follow as long as your practice is consistent.

what Claire said. I agree with him

lee\c

The shorter your development time, the more it matters. If it takes 14 minutes to develop a film, then a few seconds pouring out time makes little difference. If you are developing for 3 minutes, then it becomes more inportant, unless you are developing "to completion" (i.e. when all the silver is converted). If you are developing for 14 minutes, even an extra minute wont make much of a difference.

I'd just add that, in theory, you should be adjusting your development times to suit your tastes, your developing technique, your enlarger, etc., so it shouldn't matter, just as long as you're consistent. For instance, that 14:00 time for Delta 100 in Rodinal is exactly what's in the MDC; however, you might find that it produces negatives that are a bit overdeveloped (just hypothetically). The solution isn't to change how you time the development process, but to change the developing time (say, to 13:30). Then when you try another film that produces negatives that seem a bit thin at the recommended time, you'd change that time rather than use another variant of your technique. This enables you to keep your technique consistent across films and developers and just vary the times.

FWIW, there are published procedures for finding the correct speed and development times for films. For instance, there's this one (which has a second part). I'm pretty sure I saw something similar on Kodak's site (or perhaps it was Ilford's), but I didn't save the URL.