PMK Pyro and Tri-Xgreenspun.com : LUSENET : Large format photography : One Thread
Just starting to explore pyro, and wanted to begin with roll film. Does anybody have times/temps/EI starting points for 35mm Tri-X and PMK pyro? The Gordon Hutchings book seems to refer only to Tri-X sheet film. Pls pardon the non-LF question, but I suspect, like me, that many of you still use 35 along with large format. Thanks!
-- John Sarsgard (Endive4U@aol.com), December 02, 1998
John, Just as a starting point, you might try the following for 35mm or 120 Tri-X in PMK (with rubbber gloves on):
EI--hard to suggest, everyone has different equipment and metering methods, but I use EI 200 with a modified Pentax Spot meter; NikonTTL a bit higher, depending on metering method.
Developer dilution--500 ml water + 5 ml Pt. A + 10 ml Pt. B stock solutions.
Development time--7:30 to 8:00, two inversions every 30 seconds. (Save exhausted developer for re-stain step).
Note: If you are into the zone system with 35mm, you'll have to determine your own precise expansion/contraction times (n+1, n-1, etc.), or just follow Hutchings' guidelines for sheet film, applying similar % increases/decreases. PMK's yellowish-green negative stain makes densitomter measurements difficult, particularly with small negatives.
Plain water or weak stop bath for 1:00 or so.
Fix--Use non-hardening fixer to alllow proper re-stain of megatives. (Photographer's Formulary sells a good one, or just use the Kodak stuff, without the hardener added.)
Re-stain (Immediately from fixer, no wash)--2:00, with a bit of agitation.
Wash for about 20:00.
This should get you started. Sergio.
-- Sergio Ortega (firstname.lastname@example.org), December 03, 1998.
For Tri-X in PMK, I use an ISO of 250, develop for 10.5 minutes @ 70F. Stop in plain water, fix in Formulary alkaline fixer (I forget the catalog number) and then wash normally, using Perma Wash or Kodak Hypo Clearing Agent before washing. Immersion in the spent developer after fixing is not necessary if you use an alkaline fixer. You might also try Ilford Delta 400, exposed at ISO 100 and developed in PMK for 7 minutes @ 70F; Ilford Delta 400, exposed at ISO 320 and developed in PMK for 9 minutes @ 70F; Ilford FP4+ exposed at ISO 30 and developed for 6.5 minutes @ 70F; Ilford Pan-F exposed at ISO 30 and developed for 7.5 minutes @ 70F. I find these combinations work for both 35mm and 120. Of course, your times and speed ratings may be different.
-- Peter Hughes (email@example.com), December 03, 1998.