FomaPan 100, what gives?

DREW WILEY said:

Doremus - I get zero residual magenta dye stain with TMax films. It washes right out. I use alkaline TF4 developer.

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Drew,

I've posted about this in the past. It is still haunting and puzzling me. Some batches of TMY come out just fine. Others are left with a dark blue stain that is dense enough that it almost obscures the image. The residual dye (wherever it's from) rather quickly turns bright magenta in an alkaline bath and dissolves away.

Here's a link to my earlier thread on the subject: https://www.photrio.com/forum/threads/tmy-dense-bluish-base-fog-cause.121374/ Post #13 has the pix of the dye turning magenta in the alkaline solution.

I use PMK, a half-strength acetic-acid stop and good old Ilford Rapid Fixer (sometimes at 1+4, sometimes at 1+9 when I've only a few negs to develop). 320 Tri-X comes out fine every time. My new box of TMY is exhibiting the blue stain. It comes out in the alkaline bath (lately, I've just been returning the film to the used PMK, which does the trick too).

I'm still flummoxed, but at least I've solved the problem.

Best,

Doremus

Hmmm... That's never happened to me with any film, although I do get about .04 density of residual magneta remaining with FP4, a very small amount which bleaches out on its own with some UV enlarging light over time. Never blue, and never any residual color at all with TMax films. And this is consistent whether I'm doing roll film in hand-inversion tanks or sheets in trays. I'd have to try replicating your issue in rapid fix. I wonder if there's something different about your agitation regimen. You've already tried both citric acid and dilute acetic acid stop. I use quite weak acetic acid. Something of a mystery to me. Are you using hard tap water? (???)

It's likely the layered dye sensitisation technology or similar - I've had similar headaches with 400TX. I suspect that under specific circumstances the Rapid Fix is just acid enough to not enable the residual dyes to effectively de-mordant - while C-41 fix (near neutral) de-mordants them very efficiently (if you don't mind lurid purple or pink fix, depending on what you've been processing). With an efficient wash afterwards, they clear down to very low levels of residual dyes after the C-41 fix.

Just bought some more FOMA 100 and will commence my testing with PyroCat-HD and Rodinal. I will cut one roll up into 3 pieces to be processed as follows:

Film rated at 64asa.

1. PyroCat-HD semi stand, 27 minutes. 1:1:100 (just like the first try)
2. PyroCat-HD regular development, 9 minutes. 1:1:100
3. Rodinal stand development 1 hour 1:100 (might give it a little jiggle half way through)

Ilford Hypan fixer, water stop.

Sorry to get this thread back on topic lol.

Hope to have this done by early next week.

DonW said:

Just bought some more FOMA 100 and will commence my testing with PyroCat-HD and Rodinal. I will cut one roll up into 3 pieces to be processed as follows:

Film rated at 64asa.

1. PyroCat-HD semi stand, 27 minutes. 1:1:100 (just like the first try)
2. PyroCat-HD regular development, 9 minutes. 1:1:100
3. Rodinal stand development 1 hour 1:100 (might give it a little jiggle half way through)

Ilford Hypan fixer, water stop.

Sorry to get this thread back on topic lol.

Hope to have this done by early next week.

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I'd strongly recommend adding a regularly agitated 1+25 or 1+50 Rodinal test to this as well.

Maybe I will do a 1:25 instead of the 1:100. I really like the look of the 1:100 but for MF it's really not necessary.

Thanks,

Eric

Mystery solved. For the first time since I started using PyroCat-HD (I'm a friend of Sandy's so I got in on it early) it discoloured (plus stained) the film. The part of the roll developed in Rodinal was perfect, both parts developed in PC-HD came out purple. Very weird. No idea why this happens. I have used lots of other emulsions and have never had this happen.

I like to keep my workflow nice and standard so won't be trying Foma 100 in120 again.

Don.

Glad you seem to have got to the bottom of this! I think I only have a few shots of FOMA 100 in 4x5 everything else is 200 for me. I'll see what i can replicate with this however the only other developer i have on hand is Caffenol. If anyone else in the thread would like to join in and post results as I would love for this to be as confirmed as possible and put to bed.

From what I have read Foma 100 in 120 is a very separate beast.