Identifying exposed, bulk loaded FP4+ and Delta 100 films

[bottlegardener]

Hi, I got a bit mixed up and I have a few bulk cassettes with Delta 100 among a pile loaded with FP4 Plus that I need to develop. I was just wondering if there is a simple test I could perform, preferably on the leader as these are all short test rolls?
I still have some bulk FP4 Plus that could use as a control.
Would timing the blackening of leader clips in developer be a valid approach (FP4+ has a much longer development time for HC110)? Or perhaps timing the clearing time in fix?
Thanks in advance for any tips.

 

[MattKing]

First, I would compare the appearance of the leaders in the light with an identified example. You may find that the emulsion sides actually look different.
The FP4 + will probably fix faster, so a clearing clip test in fixer may also answer the question:
https://www.photrio.com/forum/resou...ixing-procedure-for-black-white-negatives.75/

 

[bottlegardener]

Thank you very much for the tips Matt. I'll check the leader emulsions under better light right now.

Edit: in the unlikely event someone else repeats my mistake, Delta 100 has a light mauve tint on the emulsion side while FP4 Plus is more beige.

 

[AgX]

To be on the safe side, take unexposd snippets, mark them and develop them for the edge signing to appear.

 

[Maris]

I'd just develop them the same time in the same tank with the same developer. The differences in developer response are small. For example with ID-11 at 20C both films have a developing time of 8min 30sec. Provided these films have adequate exposure the negatives should be good.

 

[RAY WILSON]

I’d stand develop them in Rodinal, 1:100 for one hour. A rather film agnostic approach. Some say to wash in water first.

 

[pentaxuser]

I’d stand develop them in Rodinal, 1:100 for one hour. A rather film agnostic approach. Some say to wash in water first.

Wash in water? Some, on seeing you use the phrase "stand development", are liable to suggest that you wash your mouth out with soap and water as well

pentaxuser

 

[destroya]

both of then do develop in almost the same time, but the issue is fixing as delta take almost twice the time. to be safe i would just give both films the delta fixing time