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Removing Magenta Dye from 400Tx


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6-7 minutes in TF-4 plus a wash of about 20-30 minutes in running water around 70-deg. F usually works for me, no HCA or Permawash, though there could be an issue of water hardness to consider that's causing problems in your case.

 

Alternately, I've used 4-5 minutes in Zonal Pro Rapid fixer without the hardener, rinse, Permawash, and about a 20 minute wash, and that seems to clear it.

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It's an issue because people are used to B&W film having a clear to slightly gray base, not a pink or blue (depending on brand) tint. Nothing else -- I've heard no reports of problems printing or scanning the negatives with this residual tint.

 

I just processed my first ever 400TX today, and while I can't say much for the images (developing experiment; learned something, but no images to show), I didn't find the residual tint excessive after ten minutes in paper-strength Ilford Rapid Fixer.

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The only dye in Tri X is the antihalation layer. I still presoak for a minute in filtered H20, then soup in D76 1:1 for 11 minutes. The rest is a couple of quick stop baths, Kodafix, rinse, HCA and Photo-Flow.

 

My wash time is 5 minutes and the film base turns out gray every time.

 

What developer are you using? It may be that the Metol in D76 is especially good at removing the antihalation pigments and I don't know it.

Best Regards - Andrew in Austin, TX
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To get any residual magenta dye off almost any film is to put it on a light table for about 15 minutes, although that time depends on how much dye there is left. This will clear the film.

 

The reason for the concern, is besides scanning negs, there is some opinion that the extra magenta can affect contrast grades when using VC paper and filters. I have never tested this, nor cared to, because it is easy enough, by the above method, to get rid of it.

 

Hope this helps.

 

Alexis

 

www.alexisneel.com

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Try an initial wash in a 5% solution of sodium carbonate. An alkaline wash is more efficient because it opens up the gelatin of the emulsion. Then I suggest you use the Ilford washing method. I use a variation on this using the basic three changes of water but 10, 20 and 40 inversions of the tank. This is much more efficient than allowing water to flow through the tank and saves both time and water.
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"Then I suggest you use the Ilford washing method. I use a variation on this using the basic three changes of water but 10, 20 and 40 inversions of the tank. This is much more efficient than allowing water to flow through the tank and saves both time and water."

 

Chrish, how have you tested the efficiency of the two methods? Or do you have some references on this?

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I fought this for a while and read all the "cures." The only real solution IMO is to go to a two-bath fixing method. Do some Googling on this in the newsgroups. Recently I ran a roll of T-Max 100 and Neopan 400 in fixer that should have still been good based on the amount of film run through it. I keep two snippets from each film. I fixed them for three times the "normal" amount and then took one snippet from each emulsion and and put them into fresh fixer. In just a minute each film was noticeably clearer than the one that only had the first fixer. Two-bath fixer. Give it a try. I'm now a believer.
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OK, thanks for all the thoughtfull suggestions.

 

First, let me say that I have no problem with TMX or any other film. The new 400TX seems to be a different animal. I tried sodium sulfite, 3 fixer baths (Rapid fix and TF-4), EDTA, PermaWash, etc. I even exposed it to 30 minutes of UV light under my Platinum exposure unit as I read that the dye is light sensitive and will fade. Nope, no such luck.

 

SOLUTION FOUND!

 

I found only one thing that works.........drum roll please.

Good old H2O.

 

After all the efforts, I placed a clip test in non-running water and soaked for 60 minutes. The magenta is gone and the polyester base is clear and bit gray as Kodak says it is.

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Chris: My only concern about using sodium carbonate *before* development is that, if not rinsed out before adding the developer, it can cause foaming during agitation and may alter the characteristics of the developer. I've tested the former (it definitely aggravates foaming) but not the latter.

 

Severi: Chris is absolutely correct about the Ilford archival washing sequence getting rid of any film base tint. I use this method routinely, tho' I've altered it slightly: 30 agitations followed by two cycles of 60 agitations each. It's simply easier for me to remember, and I don't try to time it by a watch. I just get into a steady rhythm.

 

When I pour out the first tankful of rinse water most of the dyes come out. The second tankful is very slightly tinted. The third tankful is clear.

 

I always follow up with a final tankful of distilled water and Photo-Flo, which I agitate for 15 seconds to mix it up (I add a couple of drops per tankful) and let it sit for a minute. Only once have I ever detected any residual color in this final rinse and that was when the film had overlapped slightly at the center of the stainless reel. Naturally, the emulsion and/or film base was still full of anti-halation and/or sensitizing dye in this small section. The rest of the negative strip was neutral gray.

 

I firmly believe that simply agitating the rinse water in the tank, per the Ilford method, will cure this "problem." I simply haven't found it necessary to fix for protracted periods (unless the fixer was nearly exhausted) or resort to using other chemical additives. Maybe it's my rural well water, which is run through a salt-type water softener and then filtered.

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Severi,

 

No, I haven't conducted tests but Ilford have and achieved archival quality negs with three changes of water and 5, 10 and 20 inversions of the tank. Now, three tanks of water is 1,800 ml which is just over 3 pints. Compare that to a tap running for 20-30 minutes. It saves a huge amount of water. I started using the Ilford method when we had droughts in order to conserve water.

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Lex,

 

Sorry I missed your response. I didn't make it clear that I was referring to washing after fixing. I had not considered an alkaline wash before development but I share your reservations about such an idea. Any residual alkali would indeed affect development.

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