Carolus
Hello everyone,
I’m not only new to this forum, but I’ve only been developing black-and-white film at home for a few weeks. Yesterday I had a go at developing a roll of Kodak T-Max 400. I started by developing it with Adox Rodinal (1:25), for 6 minutes at 20°C using the Agfa agitation method. I didn’t use a stop bath. I simply changed the water completely 3–4 times. Fixing was carried out with Adofix Plus (approx. 4 minutes). After the final rinse and the final treatment in Adoflo, the following problem became apparent: I noticed a narrow purple streak on the perforation edge of the negative. The strip is a similar colour to the liquid I pour away after development. This hasn’t happened to me when developing Adox CHS II or Agfa APX (new). What could be the cause? Many thanks in advance for any helpful advice!
Wolf_XL
...probably fixed for too short a time and/or not rinsed thoroughly enough. Flat-crystal films such as T-Max require roughly twice the fixing time of conventional films. The fixing time also depends on the fixer used and can be easily determined by a clarity test (dip a film scrap into the fixer and measure the time until the film scrap is clear = clarity time). For conventional films, the fixing time is equal to twice the clarity time; for flat-crystal films, three times the clarity time should be assumed.
Carolus
Thanks for pointing that out. The coloured edge on the perforation strip that I described is about as wide as the slot into which I load the film. My fixing time was only about 4 minutes, during which I kept the canister (Jobo 1520) constantly moving. I followed the instructions on the Adoxfix Plus bottle. I hadn’t realised until now that flat-crystal films require a longer fixing time. I’ve already scanned the negatives and am happy with the result. Should I re-fix the whole roll of film?
KlausWehner
Hello and a warm welcome to the forum.
Wolf has already covered the essentials: all flat-crystal films generally require a longer fixing time.
I would determine the standard fixing time and multiply it by 3.
T-Max 400 has a reddish tint. If any residues of this remain in the film after the entire development process, it isn’t a major issue at first. It doesn’t cause any problems.
You describe a situation where the tint has only partially remained at the edges. This suggests an irregularity.
Perhaps the volume of chemical was too low? Perhaps the film came into contact with the spool at that particular point?
It’s hard to say for sure from a distance.
My advice: first rinse the film briefly, then fix it thoroughly again (perhaps for 7–8 minutes), and then rinse it well.
Conclusion: the colouring isn’t a major issue; the fixing time was probably too short. That should be corrected.
Best regards,
Klaus
Carolus
Thank you very much for your help. As suggested, I have just placed the film – which had already been cut into strips – in a fixing bath for another 8 minutes. The discolouration along the perforated edge has disappeared. Finally, I rinsed it again and ran the film through Adoflo. The negatives should now retain their quality for years to come.
KlausWehner
All's well that ends well :-)
