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I've been using an old Calumet 8x10 negative holder that is solid plastic to develop 8x10 film. Using this holder, the emulsion side gets fully and evenly processed. But post fixing, some of the anti-halation backing can remain on the film. What remains appears to be removed during washing.
As to my question, will washing adequately remove this backing, or does it require some sort of chemical processing that's inherent in the developing/stop/fix phase of processing?
May be of interest:
https://www.largeformatphotography.i...highlight=drum
Neil,
As far as I know, the anti-halation backing is water soluble, meaning that the wash should do the job. With all the films I use, the anti-halation dyes come off completely in the pre-soak.
The problem with pinkish or blueish casts to T-max and other films is related to retained sensitizing dyes, not the anti-halation coating. These are more difficult to wash out and often benefit from a slightly alkaline bath and/or extra fixing time.
If the negatives look good, then there's no problem. I can't imagine that a little retained, but invisible, anti-halation dye would cause damage to the negative, even over time. The main thing is that the negative is clear enough to print/scan.
If you're worried, do a quick test. With the room lights on, place a generous drop of fixer on the emulsion side of a dry film strip and allow it to do its job fully, i.e., clear the film. Don't get anything on the non-emulsion side. After the spot has cleared, rinse off the excess fixer and then drop the whole strip in a tray of water and soak off the anti-halation coating. The spot you fixed should be fully clear film base only.
Best,
Doremus
TMax films are among the easiest or fastest to wash out any residual stain completely. I use an alkaline fixer (TF4).
Thanks for the responses. I feel much more comfortable that I'm on the right track.
I plan on getting a traditional 8x10 hanger. While I wouldn't use it for developing, I can use it for washing to make sure that both sides are thoroughly washed.
I found that in some B&W films a lot of the colored dyes come out in the wash aid (I typically use Perma Wash). You might consider doing a wash aid step in the hanger rather than the holder.
Good idea. Probably should, anyway.Quote:
Originally Posted by reddesert
All be it years old, I just unsealed a "fresh" bottle of Perma Wash.
Thanks.