Developing C-41 film (Jobo?) tips/advice/etc

Sirius Glass said:

Or just keep the negatives in the stabilizer longer than the 30 seconds.

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I got drying marks even after 1 min in the stab...maybe longer would be better?? Photoflo fixed the problem.

Pasto, for both color film in stabilizer and black & white film in PhotoFlo, I would suggest up to say 2 minutes [who is counting] while agitating the film. When I process my 4x5s in have them in a 1 liter cubic plastic box. I put the negatives in one at a time, then I take the first in pull it up and rotate it 180 degrees. I repeat this with each negative several time. For 35mm and 120 film, I flip the film over in the container several times.

If you still have streaking with the color film, I would recommend:

1. Rewetting in stabilizer, and if that does not help
2. Send a PM to Photo Engineer aka PE for advice. He has a career of experience with these things and really advises against using PhotoFlo on color films.

I have concerns about the archival effects if you use PhotoFlo on color films.

Steve

I've already stated here in an earlier post in this thread or elsewhere on APUG:

1. Do not use anything but Stabilizer or Final Rinse as the last step in ANY color process or you risk losing image stability.

2. Photo Flo, Stabilizer or Final Rinse is fine in reels. I have been using it in my Jobo for decades. The key is a hot water wash of the reels and tanks after the process to remove or prevent gunk!

3. When using a tank with any film, a prewet is just about mandatory. With color it tempers the tank accurately (see the test using various methods elsewhere on APUG). With color and B&W it also helps reduce air bubbles (pinholes) by prewetting the film. It used to be in all Kodak instructions but has been omitted from their instruction manuals in the last decade or so.

4. Do not agitate in a final bath so that it foams, and do wipe the film gently with a sponge wetted with the final bath or use your fingers or a squeegee. This assumes a dust free environment so that scratches are not introduced by the "rubdown" and with low agitation the bubbles just don't have a chance to form.

This is based on 5 years of production experience at a Photofinisher, and in the Military and 32 years of R&D at EK along with decades of personal work producing thousands of negatives and prints from 35mm to 4x5.

PE

Photo Engineer said:

I've already stated here in an earlier post in this thread or elsewhere on APUG:

3. When using a tank with any film, a prewet is just about mandatory. With color it tempers the tank accurately (see the test using various methods elsewhere on APUG). With color and B&W it also helps reduce air bubbles (pinholes) by prewetting the film. It used to be in all Kodak instructions but has been omitted from their instruction manuals in the last decade or so.

PE

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Actually Kodak didn't omitt from their instructions but specifically cautions against using a pre-soak:

'Tube is loaded with film and ready for processing. Determine the best
time by calibrating the tube. See Process Control and Adjustment. Do
not immerse the film in a warm water pre-soak. Warm-up step is
done by warming the outside of the tube with hot air or in a
tempered water bath." Using KODAK FLEXICOLOR Chemicals, page 3-6.

Perhaps the nature of the film changed requiring a pre-soak to be eliminated?

It's good to hear that a hot water wash clears the reels of the gunk because that is what I have done for years until recently switching to unspooling the roll and immersing it in the PF/Stablizer/FR.

Thomas

Tom;

AFAIK, a presoak does nothing to Kodak film one way or another. It does benefit from the POV of pinholes and from poor air tempering before starting development. Read the other thread for real data. I have been using a presoak for over 30 years with no observable harm. I learned to do it from the old Kodak instruction books.

However, we never used a presoak in R&D nor do machine processes use one. The method used in a Jobo differs enough that a presoak can be used handily to aid in overall quality. When I worked on Kodacolor Gold 400, we used large open glass tubes with racks to hold film and we used Nitrogen burst agitation. Roller Transport machines use counter current flow agitation. So, the drum or tank processes differ substantially and can introduce artifacts if the film is not prewet. This is my opinion and my experience both!

Others have verified this in posts here on APUG.

PE

I had random problems early on that were diagnosed by an experienced color film processor who advised me to always temper my film, reels, and tanks with a tempered water wash for at least 1-2 minutes before the developing step.

I adopted his recommendation in 1987 and have had no recurrence of the problems. It does the film no harm that I’ve seen. Therefore, it’s part of my standard film processing recipe.

Photo Engineer said:

By resoaking them in Photo Flo, you removed the stabilization capability imparted to the film by the original stabilizer. To do a proper job on modern color negative films you must use a Stabilizer or Final Rinse with the proper chemistry before storage.

PE

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I've read that modern films (Kodak films at the very least) don't actually even need stabilizer. Having very minimal knowledge of film chemistry, I cannot confirm this, but this was the only way I could see myself doing it. The Unicolor stabilizer is awful and a lot of people have trouble with it leaving watermarks, what other options do I have?

EDIT: Just read through the last page and I missed some stuff earlier. I've been doing around 1 minute in the stabilizer bath with about 20 seconds of that minute agitating.

I would like to see your sources that say modern Kodak (or Fuji) color films do not need a stabilizer. Kodak and Fuji once supplied a stabilizer, but now supply a final rinse. The contents are slightly different, but both are intended to stabilize your film against degradation.

If the Unicolor stabilizer is not to your satisfaction, use the Kodak or Fuji variant. It is inexpensive and can be purchased from many sources.

PE

Since getting my Jobo, I've been doing stabilizer in a separate (1L ice-cream) tub after unspooling the film. I recently realized that that was causing small scratches and abrasions of the film, so I think I'll do stabilization in-spiral from now on. Maybe in-tank, maybe a separate container, but I don't plan to run it through the lift - spiral and tank is much easier to wash.

You are right. I never use the tank/spiral on the Jobo. I use it in the sink for stabilization.

PE