OT: Developing an unknown 120 film

[welly]

Not sure if anyone saw it but I mentioned in a post I had a film of (mostly) unknown type that needs developing. I know it's an Ilford and I know it's one of Pan F (50), FP4 (125) or HP5 (400). I suspect it's either FP4 or HP5 though. Can anyone suggest what would be the best approach to developing this film without losing the contents through over or under developing?

Cheers!

[Pat Kearns]

Looking at my old Photo Lab Index for Ilford Pan F & FP4 using Ilford developers:
Pan F at 68F
Developer Dilution Time
ID-11 1 + 1 7 minutes
1 + 3 11.5 minutes
Microphen 1 + 1 4 minutes
1 + 3 7 minutes
Perceptol 1 + 1 10.5 minutes
1 + 3 13.5 minutes

FP4 at 68F
ID-11 1 + 1 9 minutes
1 + 3 12 minutes
Microphen 1 + 1 7.5 minutes
1 + 3 15 minutes
This is a starting point, hope it helps.

[David Karp]

Develop it in a 2 bath developer like Diafine. Time and temp won't matter in Diafine.

[JRFrench]

Unwind it a little in the darkroom, snip a frame or so off, dev that to read the film name on the edge of the film, assuming 120 film has this like 135, I don't know I've never used it.

[welly]

Unwind it a little in the darkroom, snip a frame or so off, dev that to read the film name on the edge of the film, assuming 120 film has this like 135, I don't know I've never used it.

Ah awesome, good thinking. I'll try that.

[Ash]

Make sure you take it from the right end so you don't end up losing a photo from the roll....

From a Blad you find the excess at the non-tap end.... but on all my folding cameras it's either on the tape end, or there's an inch either end I think

[Wallace_Billingham]

Do it in Rodinal 1:100 for 10 minutes at 68 degrees. it won't be perfect developement it will get you very usable negs no matter what the film stock

[JRFrench]

Make sure you take it from the right end so you don't end up losing a photo from the roll....

From a Blad you find the excess at the non-tap end.... but on all my folding cameras it's either on the tape end, or there's an inch either end I think

Losing one shot is better than losing 12

[Brian Schall]

Or you could use Rodinal 1:200 for 1 hour. Agitate the first 30 sec and then come back in an hour and finish it up. This seems to work with almost any film.

[sanking]

Develop it in a 2 bath developer like Diafine. Time and temp won't matter in Diafine.

I second the two bath approach and Diafine should give maximum shadow detail without the risk of blowing out the highlight.

If these were my negatives I would not seriously consider any other approach other than two bath development.

Sandy King