Highest safe temperature for B&W film?

Вormental_old · Oct 12, 2020

I am starting to be pissed at Fomapan in this thread, as they keep selling film that needs insane amount of pre-soaking (20 minutes) to dissolve its AHU fully.

I am thinking to speed this up by pre-soaking in the hottest water possible. But the question is: how hot can the pre-soak water be? I have two ideas:

Find the hottest temperature recommended for any developer+film combination by any manufacturer. Turns out, the highest I found was actually from Foma, they have times for 30C.
Use the C41 time, i.e. 38C

Thoughts? Mind you, this is pre-soak water we're talking about. I plan on cooling the film after pre-soaking and then developing at my regular 21C.

Deleted member 88956 · Oct 12, 2020

All I will say is ... experiment at your own mercy, especially if you intend to see what wrinkled up or emulsion slide looks like.

I have no idea what that thread is talking about. people will find a problem, then never let it go. Not involved in that thread and don't know whether Foma has put out a bad batch or something entirely unrelated is causing that kind of a problem. I never pre-soaked any film with AHU in order to flush it all out before development and I don't think this is the problem here either.

Ian Grant · Oct 12, 2020

I've shot a lot of Foma film 120 and LF over the past 12+ years, quite of lot of it while living in Turkey where I process at the ambient water temperature which is a consistent 27ºC from early Spring to late Autumn, with no effort I can keep the whole process cycle to 27ºC +/- 0.2ºC.

I never pre-wash it's an unnecessary step. I'd look at filtering your water that may prevent your white dots, use a de-ioniser if needed.

Ian

russell_w_b · Oct 12, 2020

The Ilford developing temperature compensation chart ranges from 18°C to 27°C, and I've used these values with other film (including Foma 400 ) to good effect if I happened to be a couple of degrees over or under 20°C.

But they also say that uneven development may result if the time falls below 5 minutes, so you may need more dilute developer to keep above that, if your mix is 27°C.
--

R.

koraks · Oct 12, 2020

Вormental said:
I am starting to be pissed at Fomapan in this thread, as they keep selling film that needs insane amount of pre-soaking (20 minutes) to dissolve its AHU fully.

Doesn't sound familiar. I've used many many rolls & sheets of Fomapan. The AHU dyes wash out just as easily as with other non-TMAX films. TMAX is much more of a bitch to get the pink dye out of. With Fomapan, a normal processing regime of develop - stop - fix - 4 water washes (Ilford method) is sufficient to get the dye out. If this doesn't work for you, something very odd must be going on in your darkroom. I never had the kind of spots you posted and I doubt they have much to do with AHU dyes. Are they green on the negatives?

R.Gould · Oct 12, 2020

I have used a lot of Fomapan both 200 and 400, in 35mm and 120, it is my main film for at least 25 years, and I have never ever pre soaked, don't need to, the green anti halition layer normally comes out in the developer, I use either ID11 stock or Rodinal 1/50,the developer is green when poured out, stop bath is very slightly green, fixer is clear, Ilford wash method water is perfectly clear when poured out, , green in ID11 does not affect the developer at all, I just go on using it as per Ilford instructions, gets greener the more 129 I develop, I simply can't see the need for a pre soak

AgX · Oct 12, 2020

Вormental said:
I am starting to be pissed at Fomapan in this thread, as they keep selling film that needs insane amount of pre-soaking (20 minutes) to dissolve its AHU fully.

-) pre-soaking is an american concept I only learned about here at Apug

-) bothering with emulsion dyes at standard processing I only learned about here at Apug

-) Foma films do not even have an AHU.

-) dissolving an AHU would mean ruining the film

So much about misconceptions.

koraks · Oct 12, 2020

AgX said:
Foma films do not even have an AHU.

Probably not an AHU. Just dyes, at least in 120 and sheet film. Nothing in 35mm.

AgX · Oct 12, 2020

Foma films with undeyed base have an AH backing layer.

Deleted member 88956 · Oct 12, 2020

AgX said:
-) pre-soaking is an american concept I only learned about here at Apug

-) bothering with emulsion dyes at standard processing I only learned about here at Apug

-) Foma films do not even have an AHU.

-) dissolving an AHU would mean ruining the film

So much about misconceptions.

The driving motto of it all: if there is no problem, we'll will find it and prove it does exist.

I nearly said in a different thread: it appears digital is taking over analog, mulling over every single bit that sometimes not even remotely looks like trouble, but in digital there is always trouble, some sort of lacking feature, inadequate specification, "imperfection" (only seen at 100% pixel level) etc.

Athiril · Oct 12, 2020

I’ve used 29 degrees regularly with Xtol replenished for Delta 3200 because I don’t wanna be there developing forever.

lve also ran high temp in Xtol replenished higher than this, I think even 38 maybe when I converted a frontier processor to run Xtol and could only vary development by temperature. So set a temperature for lower films first like then higher later on etc. Worked pretty well.

Huss · Oct 12, 2020

I very recently developed Delta 3200 @ 90 with no issues, and Arista 100 pushed to 400 @ 95 degrees with no issues.
95 = 35C

Using Cinestill DF96 Monobath, following their instructions.

Вormental_old · Oct 12, 2020

Gents, no need to debate the need to pre-soak, or my process or quality of my water, etc. The "white dots" problem is relatively recent phenomenon and has been reported by many users here and elsewhere (large format forum, for example). This started to happen around the summer-2020 and Fomapan's support suggested to pre-soak for 20 minutes and explained that it's the AHU issue. There's a separate thread for it.

I just don't want to waste 20 minutes and looking to speed this up.
I'll try 100F for 6 minutes next time with inversions, instead of stick agitation

koraks · Oct 12, 2020

Keep in mind that foma's emulsions are not hardened to the extent of ilford's or Kodak's. 100F may be on the high side, although it'll likely survive. I'd likely go for something like 85F; that should speed things up already quite significantly compared to 70F.

BradS · Oct 12, 2020

Вormental said:
---snip---
I'll try 100F for 6 minutes next time with inversions, instead of stick agitation

..will you then slowly lower the temperature of the film/water bath to something closer to 20degreesC ? Or do you propose to process at 37degreesC ? I would think reticulation would be a concern otherwise.

Вormental_old · Oct 12, 2020

Yep, those are valid concerns. I'm willing to waste $10 on a couple of test rolls to figure all of this out.

MattKing · Oct 12, 2020

I'd design my developing regime to work best and most conveniently with non-defective film.
If you change your temperature for development, you should adjust the temperatures of your stop, your fixer, your wash-aid (if you use one) and at least the early stages of your wash as well. That is a lot of hassle.
I'd use an extra step to deal with the defect for as long as I needed to deal with it.

Rudeofus · Oct 12, 2020

Вormental said:
Yep, those are valid concerns. I'm willing to waste $10 on a couple of test rolls to figure all of this out.

You won't have to waste several rolls. Take a 35mm roll with some standard subject matter, cut off a short clip of 3-4 frames for each test. Try temperatures at 50°C, 44°C, 38°C, 32°C and 28°C. Process all future rolls a few degrees below the first test strip that survived fully intact. Be prepared to find different temperatures for different film makers.

Donald Qualls · Oct 12, 2020

Rudeofus said:
You won't have to waste several rolls. Take a 35mm roll with some standard subject matter, cut off a short clip of 3-4 frames for each test. Try temperatures at 50°C, 44°C, 38°C, 32°C and 28°C. Process all future rolls a few degrees below the first test strip that survived fully intact. Be prepared to find different temperatures for different film makers.

The underlying problem that's the cause of all this, however, seems to be present only in 120 and sheet film.

Вormental_old · Oct 12, 2020

MattKing said:
I'd design my developing regime to work best and most conveniently with non-defective film.
If you change your temperature for development, you should..

I am not changing the temperature for development, only for pre-wash, and film cools extremely quickly to ambient.

Donald Qualls said:
The underlying problem that's the cause of all this, however, seems to be present only in 120 and sheet film.

Yes. I keep forgetting to locate the batch number, as (supposedly) this is a temporary phenomenon, but so far every Foma 100 roll I got from either B&H or Freestyle was affected. I do not want to stop shooting it, IMO this film, particularly its ISO 100 variant, is truly unique, so I do not mind switching to "crazy prewash" routine for a year until retailers clear the defective stock.

Вormental_old · Oct 12, 2020

Rudeofus said:
You won't have to waste several rolls. Take a 35mm roll with some standard subject matter, cut off a short clip of 3-4 frames for each test. Try temperatures at 50°C, 44°C, 38°C, 32°C and 28°C.

The "white dot problem" does not affect the entire length of a roll evenly. Earlier frames located closer to the center of the reel, are more affected as they receive less agitation. So if I want to establish a repeatable and safe shortest-possible pre-wash routine to cure the dots, I ought to be using full rolls.

MattKing · Oct 12, 2020

Use inversion agitation for your pre-wash - agitation will be consistent throughout.

Donald Qualls · Oct 12, 2020

Вormental said:
Earlier frames located closer to the center of the reel, are more affected as they receive less agitation.

Here's a suggested test to verify that your hypothesis (about agitation) is or isn't correct: load a roll tail first and see if the spots stay near the core of the reel (at the tail) or stay at the head end of the film (now at the outer edge). Or, try inversion during your prewash, to see if that evens things out over the length of the roll.

pentaxuser · Oct 12, 2020

Bormental makes what may be a good point about how quickly pre-washed film at what may be 90F+ cools down to ambient once drained of pre-wash. What he needs, it seems to me, is for someone who knows to tell him how long he needs to wait until he pours in his dev,stop and fix at say 70F before he runs any risk of reticulation?

Anybody?

pentaxuser

Donald Qualls · Oct 12, 2020

May not be completely relevant (because C-41 films have harder gelatin than Fomapan), but I recently run a couple rolls of XP-2 Super with bleach bypass, and for one reason or another did the wash and final rinse steps with cold tap water and room temperature final rinse solution (ca. 17C in both cases). I thought I might have reticulated the film -- looked pretty funky when it was wet from the final rinse -- but it smoothed out and the grain is no worse than previous rolls of the same film. So, looks like straight from 38C to 17C doesn't cause problems with C-41 stocks.

I don't think I'd want to try that with Fomapan, however...

Highest safe temperature for B&W film?

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