Minox Film Developing Tanks

Minox Film Developing Tanks

The Minox Developing Tank, as ingenious as the camera, features spiral loading of the film around a drum assuring a free distribution of developer and even development. It is a marvelous instrument, having provided for many years, in many hands, outstanding results. Be sure to read Peter Zimmerman's article at the end of the Minox Processing Labs, Hobbyist Section.

I suspect, however, that the extreme 1:100 dilution of Rodinal, that I favor for Tech Pan (and Agfa Copex), will provide, at the 53cc capacity, insufficient developer and will accentuate the rather pronounced shoulder. I had suspected that insufficient solution might be a consideration with PMK Pyro, since it also is a rather dilute solution, but Oliver Pyper reports from Berlin, success with PMK and the Minox tank.

Tech Pan film, 25 ASA
100 ccm, PMK developer in beaker,
Minox developing tank
6 minutes at 20 deg C.

Presoak 1 min with water and photoflo
Empty presoak solution
Add PMK solution until the tank is filled
For agitation, every minute (takes about 8 seconds)

Pour out about 20 ccm of the developer from the tank into the beaker, then fill up the tank again from the beaker.

Wishing to increase the total volume while retaining the marvelous concept, I discovered a 4oz."pill bottle" that just fit the recess in the lid of a 250cc stainless steel Nikor developing tank, cut it down to just fit in the closed tank, drilled some holes in it, and slots for the ends of the film. I carefully glued a narrow plastic strip in a spiral pattern around the bottle to guide the film as I wound it. I now have a tank which permits me to wind a roll of 42 exposure Minox film, emulsion side out. I have, for 30 plus years, promised to make a more elegant version, but the original prototype still works perfectly, in spite of its appearance.

To hold the film in place, I made, with a jeweler's saw, one slot at the bottom at the beginning of the spiral, and three at the top, positioned for 30, 36, and 42 exposure lengths. I pass a half inch of film through the slot at the bottom, fold it back, and squeeze it to crimp it. Then winding the film on to the drum, I finally slide the end into the appropriate slot at the top, where it is crimped in the same manner. To secure the end for short lengths, I use the same artists tape I use to attach the film to the takeup spool..

Another alternative is a spiral reel such as the Honeywell Nikor stainless steel Minox Reel, which is used in a standard developing tank.