I've been using Rodinal for about a fortnight. Today, I decided to give Neopan 1600 a go in it. Rating the film at 800, I shot half a roll of grey card and finished it off with a few snaps around the house. As a start, I mixed the Rodinal 1:50 and gave the film 8 minutes @ 20C with two inversions every half a minute. I stopped, fixed, and washed as usual. The result was completely against my expectations. The roll came out entirely blank. There is a whisper of density on the piece of film that sticks out of the cartridge but otherwise there is nothing; not even a trace of edge numbering. I'm 100% positive that I didn't confuse the developer with the fix. The Rodinal is only a couple of weeks old. (It has become dark brown. Is that usual?) I've developed over half a dozen films using the exact same bottle without a problem. (Yes, I use it as a one-shot.) What the hell happened? I didn't think Rodinal was prone to failure. I was under the impression that it lasted forever. The only cause I can think of might be that the cylinder I mixed it in might have been contaminated with fixer. It was last used the other day to mix a fresh batch of Ilford Rapid Fix. I can't remember rinsing the cylinder before mixing the Rodinal but it's a procedure I usually carry out so I'd be surprised if I didn't. Besides, the cylinder would have been completely dry and I'm sure that any trace of fix would have been insignificant. Perhaps I'm wrong. So, any ideas? Has the Rodinal given up? Could the faintest trace of fix spoilt the developer? Might the problem have been with the film?