I figured some of my fellow Filmwasters would find this interesting. I use Photographers Formulary TF-5 Archival Fix, it seems to last forever. I usually stop using it because it gets a lot of gunk in it, not because it stops working. The gunk is the silver that has been stripped from the negative and settles to the bottom. I decided to concentrate it out to take a look at it under the microscope. I diluted out most of the fix with distilled water. I know the fix will crystalize as it dries, I've examined that under the microscope, the crystals are not very interesting.
I put a drop of the gunk/distilled water under a cover slip to take a look at it. It just looked like a bunch of grains scattered about, not very interesting. Eventually I may see if I can dissolve it and try to grow crystals but that requires some hazardous chemicals. I know nitric acid will work but I don't like dealing with that at work let alone at home.
Putting the gunk under the cover slip keeps it from drying out fast and sometimes helps crystals form. when I went back to look at it the next day I wasn't really expecting crystals but was a bit surprised at what I saw. It looks like the grains may have had some kind of ionic attractions, they formed lines and branches. Some grains just stayed spread out. You can also see at the end of each branch there thicker bunches of grain like they are leaving trails behind them.
These were photographed with a Leica IIIf using a Leitz MIKAS microscope adapter. The film is Ilford FP4+ developed in Beer.
