I'd been wondering about this.
I have a couple boxes of old 4x5 and 3a sized glass plates. I mean so old that the concept of the expiration date hadn't been invented yet, so I have no idea how old they are, except that they're likely pre-war, and you can pick which war. I tried exposing one by strips and found the whole thing was fogged black, so they've been sitting on the shelf waiting for me to figure out what else I could do with them. I'd been wondering if there was some way to "de-expose" them such that I could use them in a camera; everyone I asked assured me it couldn't be done, but this looks like it might work.
Sure they'll be slow, but they weren't all that fast to begin with...
Any suggestions specifically for these?
edit: only developer I have in the house is HC-110 at the moment (not counting the various ingredients of caffenol-C). Would HC-110 work for this purpose? I would have to go to B&H to pick up the bleach in any case, should I get some other developer?
edit: would this be safe under a ruby safelight? The plates were orthochromatic to begin with, and would presumably now be monochromatic, but it couldn't hurt to check. I'm gonna be stuck in the darkroom until they dry anyhow, I'd rather not be in total darkness.
Last edited by Shalom; 05-08-2013 at 04:24 PM. Click to view previous post history.