Developing old Plus-X film

[chris00nj]

I found some old exposed, never developed Plus-X film from my grandfather's. It is probably from about 1970. At the time, developing times for old Plus X calls for 5 minutes in HC-110 (dilution B) at 68F, or 10 minutes in dilution H. (I normally use Dillution H) I realize that I need to change developing times to compensate for the age.

A few questions:

1. How much longer should I develop the film? I was thinking about an extra 40% or 14 minutes in Dilution H at 68 F? Does that sound reasonable?
2. Would using dilution B, make a difference with older film?
3. Is it better to use a colder or warmer temperature to reduce fog?
4. Plus X from this time period was still ASA 125, right? There is no film speed marking on the film canister.

 

[sper]

At this point it's really guess work as to what what roll has gone through. I would simply increase dev time by maybe 20% and hope. Very few people can tell you exactly how to develop a film that's been sitting around for 30 years.

Temperature just increases or decreases the activity of the developer, so neither would really decrease fog. You could add a defogging agent such as benzotriazol but to what amount? Again, guess work. When I do it with papers I add a 10% solution at a time, obviously with film you don't have this option.

Sorry if my answer didn't give you any peace of mind haha.

 

[sanmich]

It's really a hit or miss.
I would use a compensating developer (emofin), and add 30%~50% developing time.