I have a pack of "Eastman Super-Speed" 4x5 film. The emulsion dates from the mid-late 20's judging by the develop by 1930 date on the box. My film data books only go back as far as 1938 and nothing is noted in them about this film.
Can anyone fill in the gaps? ASA speed, dev times, etc?
Wow!
Now, I've developed film "successfully" from as old as 1947... Not super great but usable and identifiable, not something I would use in a show but surprisingly decent that I could SCAN well enough, but 1920's! I don't know... Especially being a "fast" film, it's got to be extremely fogged.
I would highly recommend using HC-110(B) as your developer, it helps lower fog issues.
A good rule of thumb is 1 stop slower for every 10 years past the expired dated...
So if you find the speed, you would want to reduce it by .... 8 or so stops...