Using Benzotriazole (BZT or Kodak AntiFog #1)

[mattmoy_2000]

Hallo,
I have some very elderly 620 Kodak TX which expired in 1959, which I shot in a Kodak duaflex II.
I was only using the film to mess around, taking pictures of days out etc., about a year ago. Unfortunately, the last picture I took of my late grandfather is now on this roll and I'm rather more concerned about getting an image out of it than I had intended to be.
I asked for some advice on a Flickr group a while back and was advised to get hold of some BZT from Silverprint in London. I have now done this and I have a 25g pot of the stuff sitting on the shelf, but alas I have no idea what to do with it. I have access to DDI (18M) water and analytical-grade isopropyl alcohol that I can use to dissolve it, but I'm not entirely sure what to do with it once I have a solution of it. I also have access to scales accurate to ~0.001g to measure the weight of solutes.
The developers I have are DD-X, TMax, Rodinal, and some old ID11, (about 15 months since I mixed that, but I can easily get my hands on some more fresh stuff). They're all fairly clean working, and I think that combined with the BZT, I should be able to make a decent development of the film; assuming I know a good time to use- or alternatively if BZT will work with rodinal stand development.
Does anybody have any suggestions or experience in this field?
Many thanks for your help.

 

[Ian Grant]

Don't add Benzotriazole, it lowers the effective film speed and you've already exposed the film. It's far better to print through any base fog. It's quite different when you use it with papers.

Tri-X back then varied in speed and dev time depending on which plant it was coated in, I have instructions from the 60's somewhere back in the UK which list different times for EK - Rochester, Canadian Kodak, and Kodak (UK) Tri-X.

I'd use the DDX as you have, use the current Tri-X time +20% extra to boost contrast slightly.

Ian

 

[hacked - sepiareverb]

I'll agree on using Benzotriazole for printing not film developing- it will absolutely lower the ISO.


Can you clip test it?

 

[MattKing]

You know which end of the film has the important image on it, so you could cut a few inches off the other end and develop that scrap using Ian's suggestion.

You could then adjust the development for the rest, based on the results.

 

[Ian Grant]

Rodinal is a very poor choice with old thick emulsion films. ID-11/D76 is best, but DDX will be just as good. HC110 is probably best avoided as well as it gives less film speed in practice.

Ian