PMK questions

[Ben Calwell]

I don't have Hutchings' "Book of Pyro." In it, does he mention how long PMK will keep on the shelf? I've got half a bottle of solution A (or is it solution B) left from a purchase of nearly two years ago. I developed some "new" Tri-X 5x7 in it last night, and it seemed fine, except for one scene that was taken in the woods. That scene was early morning, with slight fog. Long exposures of 13 seconds were required, due to reciprocity failure (indicated exposure to place a tree log on Zone V was 4 secs. I gave 13 based on experience with "old' Tri-X). In spite of the long exposure, I developed this neg for my normal 15 minutes at 72 degrees because of the flatness of the scene and because I use an old convertible Symmar, which renders everything a bit soft, anyway. Nevertheless, this neg looks flat (haven't printed it yet, maybe I'll prove myself wrong when I do). I've tried extending dev. times before with this old lens and PMK, but anything past 15 minutes doesn't add anything. It's as if it plays out after 15 minutes of tray processing. I've ruled out old PMK because my other neg looks great. Is it just the morning fog making everything look flat? It actually wasn't that foggy out. My lens wasn't fogged, either.

[steve simmons]

Tri-X is not a good film for extended plus development. It only goes so far.I do not think this is PMK problem (I like the PMK and Tri-X combo but not for anything more than plus 1).

I have kept the A and B solutions going for years. I just keep adding more as I need to.

steve simmons

[ronald moravec]

Stock keeps for a very long time. Mixed and exposed to air, the life is very very short. Tray development is exposed to air and the developer turns red-brown during the development cycle. Therefore the time/temp has another variable called oxidation.

My best results were in a jobo drum using the six sheet reel and a sealed tank. Times are much shorter and the used developer comes out fresh as newly mixed. Agitate by inversion. After adding the lid, add more PMK so there is little air space, hence oxidation. Some air space is required to promote agitation.

Roll film in a sealed tank as opposed to a lift rod technique produced a similar effect.

[Bill_1856]

Just buy the book. It ain't all that expensive.

[Ben Calwell]

Thanks, everyone. You're right, Bill. Or maybe I'll put it on my Christmas list.

[Jerry Flynn]

You said that you had not printed the neg yet. Conventional wisdom is that PMK negs will look thin (perhaps flat) because the stain provides additional density beyond the silver density we are accustomed to looking at. Perhaps it will print a bit contrastier than it looks.

[Bulent Ozgoren]

Use Pyrocat-HD instead. I used PMK with FP4+ and HP5+ for two years and changed to Pyrocat-HD last year. I am extremely pleased with the results now. Pyrocat will give you even development.