How to prevent purple streaks on TMAX100 in Jobo 3005greenspun.com : LUSENET : Large format photography : One Thread
I am a beginner at LF. I have started using a Jobo 3005 to process 8x10 TMAX 100 film. I have been using D76 and then fixing with plain jane Kodak fixer. I have been placing the emulsion side toward the hollow center. I am getting purple lines where the film apparently is overlapping. I am fixing for 13 minutes and I am still having some problems. Any help or ideas would be greatly appreciated. Sincerely, Jerry
-- Jerry Cunningham (email@example.com), May 04, 2002
Jerry I'm going to suggest that the purple you see is the unfixed film due to the fixer not being able to reach it. T-MAX films are notoriously purple if incompletely fixed and refixing this film in a tray until the color disappears should do the trick.
-- Gary Meader (firstname.lastname@example.org), May 04, 2002.
What you might be seeing here is the antihalation layer. This is normally removed during development, but if you have the back of the film pressed against the side of a tube, it might not be entirely washed away.
With TMX, I've gotten purplish blue blobbies around the middle of 4x5 sheets.
You can remove them by soaking the film in a tray with Kodak hypo clear. Plain sodium carbonate in water will also do the trick. I've even used Rodinal to do this.
If this is your problem, you can remove the stain from fixed and dried film. Just soak until they look clear, then go for a while longer. Wash and dry again, of course.
-- mike rosenlof (email@example.com), May 04, 2002.
Although I'm not familiar with the 3005 drum, I think you're getting undecolorized dyes where the film presses against the drum walls.
You don't have to fix forever. Give a normal fix time, whatever Kodak recommends. Then fish the sheets out of the drum, give them a bath in hypo-clear in a tray, then wash and dry. For HCA you can use any commercial solution such as Orbit Bath, Heico Perma-Wash etc or you can mix your own by dissolving around 25g sodium sulfite and 5g sodium bisulfite in a liter of water.
Give a couple of minutes in the HCA with lots of agitation, then wash for the film manufacturer's recommended time. HCA makers may recommend a shorter time but you certainly won't do any harm by washing longer. I wash 20-30 minutes.
-- John Hicks (firstname.lastname@example.org), May 05, 2002.
Make sure the tank is completely dry before inserting film. Any wet spots will make the film stick to the sides of the drum.
-- William Marderness (email@example.com), May 05, 2002.
as Mike has pointed out, in case of T-Max-Film the color comes from antihalation dyes that still resides in your film. Use a more extensive rinse cycle instead of a stop bath after development to wash out those dyes that have not been washed out by the developer (which might get saturated, especially when using low volumes in drums).
You might experience a similar effect with Ilford Delta Films. In case of Ilford Films, the color is not from antihalation dyes. Ilford uses dyes to make the film panchromatic and these should be washed out during fixing. The best way to remove either dyes is to use a two bath fixing stage. Fix half of the time in one bath and have of the time in the second. Then dispose the first bath and use the second as the first one in the next cycle. This is the best way to make sure that a T-Grain film is properly fixed and will yield the most clear base possible.
-- Thilo Schmid (firstname.lastname@example.org), May 05, 2002.
I've found a presoak to be quite effective. Fill up your drum and then let it sit for at least a couple of minutes. Drain it out, and you will see the anti-halation dye go down the drain. Then after you finish fixing (and hypo-clear), fill it up again and let it sit for 10-20 minutes. When you drain it out, you will see the water go radically pink. Your negatives should be clear.
-- Brian C. Miller (email@example.com), May 09, 2002.