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How to develop unknown (Ilford) film

RattyMouse

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While cleaning the house yesterday I found an exposed roll of 120 film that I had forgotten about. Unfortunately, the strip of paper that seals the exposed roll broke at the time so I used transparent tape to hold the flap down. As a result, I have no idea what type of film it is! I know that it's either HP5+ or Delta 3200 exposed at ISO1600. I'm not sure what is the best way to develop this film. I have DD-X on hand and the times seem fairly similar. Should I develop midway (time wise) between these two films and hope for the best?
 
Well I was going say load it in your tank, close the tank and then look at the other end of the backing paper. But alas, I just looked at a new roll of Ilford FP4+ and even on the beginning of the roll, the sticky label appears to be the only ID -- bummer! I can understand it makes the backing paper universal for reduced production costs, so I guess that is how it is!

I would probably split the difference as you suggest, maybe going a bit toward the longer time. Don't know what the numbers are, but if the exposures are pretty well optimum, I'd think a minute or so of deviance out of 10, 11 or 12 shouldn't be a total disaster. (That's what graded paper is for!)
 
Do what he said and post a pic here. Those of us who have recently processed ilford films may be able to help. Or are all of their papers the same?
 
HC-110 or Rodinal, 1:100, agitate first minute, then leave it stand for an hour.
 
Choose the longer of the two recommended times, unless you are sure that the film was exposed under unusually contrasty conditions.

Delta 3200 is an inherently low contrast film.
 

Times are 8 minutes vs 9.5 minutes. I was thinking about developing in DD-X for 9 mins.
 

Kodak D761+1 for 8-10 minutes at 20C will do the job.
 
I'd go 9 minutes but skip the last agitation cycle.
 
Why don't you try the drop test?

First, load the film in the spiral but cot the last centimetre or so. In open light, take a drop, as big as possible, of the developer you intend to use and place it on the film you have cut. At that time, start counting seconds. The film density will start to dicrease, comparing to the film that is not under the developer action, but soon it will start to increase again. After a number of seconds, usually between 25 and 70, density will be the same for both "films", the developed one and the not developed. And some few seconds later (2 or 3), developed film density will be slightly thicker, but clearly seeable than the other one. Then, stop the seconds counter.

The developing time for that film, with that developer at that temperature will be the number of seconds diveided by 4, but in minutes. For instance, in the time was 40 seconds: 40/4=10 , the developing time will be 10 minutes.
 
I'm facing a somewhat similar issue, someone  already suggested the HC-110, the Rodinal stand is an interesting idea as well.
 
For some time I learned from a friend to find a method for development time for any film.
Have you unknown film, remove a piece of film to light and put a drop of developer in an zone of film.
The place where the developer is, the filml begins to start with a lighter color and after developer the color starts to close.
Time timer for developer how the film works up the place with developer the color is the same color film (undeveloped).
Seconds (time acted developer how) necessary for the film to be the same color in the undeveloped portion developed with give us indication for the number of minutes of the film developer.
So the seconds are minutes from developing.
Anyone else hear about this test method for a film unknown?

George
 
Or just read previous posts #11 in particular.
 
Dear Ratty,

9 mins in DD-X is what I would do...

Simon ILFORD photo / HARMAN technology Limited :
 
Thank you, Simon. That does seem the simplest.
Let us know how it turns out, Ratty.
 
Practically, nine or nine and a half minutes wouldn't be a disaster, even if it was HP5+.

Theoretically, as with several preceding posts, keep the roll until time-travel is invented then go back and confirm what the film is, and stick a label to the roll. Hmmm, which means that you wouldn't have the problem, or the need to use the time-machine, then it starts getting complicated and you find that you are in a parallel universe where the roll was never unidentified . . .
 
wildbill said:
Or just read previous posts #11 in particular.
Click to expand...
It was difficult for me to be sure what the APUGer from Romania was saying but I have a feeling that his method might result in a different time from that of post 11.

Is the method in post 11 a recognised way to get to the right time? It's a new one on me.

If the frames are really important doesn't developing enough of the unexposed beginning or end of film to reveal the film's name represent a surer method as another poster advised?

pentaxuser
 
Isn't it a Watkins factor that's being applied?
Hardly new if so - been around since Eastman was a boy I think

And surely barely applicable to modern films?
 

Use a compensating developer like 510-PYRO, OBSIDIAN AQUA, DiXactol, Caffenol... The times and temperatures are the same for all films in these developers. I sometimes develop multiple rolls of completely different speeds and makes of film together with satisfactory results.

RR
 
Well, the mystery film was Ilford Delta 400. I developed it in DD-X for 9 mins and from my amateur point of view the negatives are extremely thick and dark, but I can clearly see images in them with no problem at all. Perhaps the dark negatives are totally normal.
 
If it was shot at box speed which seems likely then 9 mins is only 1 min more than Ilford's time so I'd be surprised if there is any problem with prints. In fact it surprises me that 12% extra time has markedly darkened the neg but perhaps as you say D400 negs are normally darker than you are used to.

pentaxuser
 
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