Pink/Magenta Stain (not blue, which is a different issue)

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JOR

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I understand that Cadmium was formerly used in some emulsions, suspected of being there to inhibit image regression (fading of the exposed but undeveloped image). Certainly, several sensitized material types, from more than one manufacturer, began to suffer from an increased rate of image regression at around the same time, mid-80s. Can anyone shed light on this?
 
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I understand that Cadmium was formerly used in some emulsions, suspected of being there to inhibit image regression (fading of the exposed but undeveloped image). Certainly, several sensitized material types, from more than one manufacturer, began to suffer from an increased rate of image regression at around the same time, mid-80s. Can anyone shed light on this?

This is a complete non sequitur to the material at hand, as it relates to fading before development. This process is more properly termed "Latent Image Keeping or LIK". What you refer to is not related to Cadmium and in fact, the major companies quit using Cadmium in the '60s or '70s. It was used to control contrast and overall curve shape.

PE
 

DREW WILEY

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I haven't read all the foregoing and can't even remember if I posted previously myself. But I have no problem with the residual pink stain totally clearing from TMax negs in just the first couple minutes of the final wash cycle. But I routinely use an alkaline fixer (TF4). What gives me problem is Ilford FP4. It retains about 4CC of magenta no matter what I seem to do, though this seem to diminish (fade) either after time or perhaps enlargement per se. So it might be possible to deliberately UV fade it. Otherwise I just factor it in whenever using FP4 for unsharp
color masking. With ordinary usage for black and white prints, the effect of the residual dye is negligible.
 

Old-N-Feeble

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Haven't you heard? This is all in your imagination because magenta is not a color.
 

Xmas

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You said it!
Adequate fixing is way more important than developing + or - n. As is adequate washing.

Fixing is film type, time, exhaustion and temperature dependent and under fixing looks just like bromide drag!

I always fix by inspection in day light, acid stop or acid fix or 3 mins in plain hypo will kill the film sensitivity and when the milky colour disappears you fix for twice the time again, Tx and the deltas take ages to fix, relative to HP5 or Foma400, note Foma200 is slow as well. In a multi tank you need to time for the slowest film.

Just don't worry about developer choice fix for longer...
 

lensmagic

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I am finding that it is more difficult to remove the pink stain from an overexposed negative than from a thin negative. Does this make sense chemically?
 

StoneNYC

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I would point out that aside from TMY-2, I've also had this issue with Ilford's PanF+ film, so it's not exclusively Kodak T-grained films, interestingly since PanF+ is supposedly a traditional grain film (at least to my knowledge) I wonder why it also seems to have the pink stain necessitating longer fix/wash times.

I know ilford isn't your strong suit PE but any idea why this might be?
 
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It is either a sensitizing dye or an acutance dye that is being retained. It should not matter as to image density AFAIK, but these new dyes are a different breed than the old ones (like me).

Try a mildly acid sulfite bath and see if that helps. Rewash and don't forget the Photo Flo.

PE
 

Nicholas Lindan

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Try a mildly acid sulfite bath and see if that helps. Rewash and don't forget the Photo Flo. PE

I find HCA does a very good job of getting the pink out. Keeping HCA and wash warmish at 70-80F helps a lot.

I shy away from fixing for any longer than is necessary as over-fixing can bleach away shadow detail (albeit very deep shadow detail).
 

john_s

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I find HCA does a very good job of getting the pink out. Keeping HCA and wash warmish at 70-80F helps a lot.........

A propos to PE's comment earlier about acid in some way being associated with the pink stain, would a simple solution of sodium sulfite (marginally alkaline) be actually better than HCA which is less alkaline?
 

Nicholas Lindan

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Sulfite has quite an effect on dye - but it seems it is the pH change that causes dyes to fade.

Sulfite is often added to writing paper to make it “acid free”. The resulting alkaline paper can make fountain pen writing disappear.

The effect is reversible: make the paper acid again and the color returns. Of course, then the paper rots away.

A demonstration of the effect, using ink in water rather than paper:

http://www.fountainpennetwork.com/forum/topic/231307-effects-of-ph-on-blue-black-inks/

I am under the impression that Kodak HCA is buffered to a specific pH - the ‘isoelectric’ point (and here my knowledge runs out). At this pH the gelatin no longer binds to other chemicals (hydrogen bonds?) and this helps with washing out fixer and the purple dye.

The purple dye isn’t destroyed, it just washes into the HCA - which turns a brilliant purple. Any remaining purple goes into the wash water.
 

ericdan

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After fixing and initial rinse, fill tank with water and let sit for 10 mins then dump. Repeat a few times or let sit longer.

This is the only way I've been able to get rid of the dye. No fresh fixer, no longer fixing, no hypo clearing has made ANY difference AT ALL.
 

williaty

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So I'm having my own battle with what I think is the same issue. I'm using HP5+ in 120 and 4x5 sheet and running the following processing pattern:

All steps at 20C in a Jobo CPP2 at motor speed P
1) Pre-wash of 5 minutes
2) XTOL 1:1 for 10'15" (120) or 10'30" (4x5)
3) 1 minute stop in citric acid at 1g/100mL
4) Fixing with TF-5 1:4 for 4 minutes (as per TF-5 instruction sheet for "other films")
5) 5 quick fill/drains of the tank to wash the Jobo lift system out
6) 6 minutes running water washed in tank (hose stuck down the central core with the lid still on) based off TF-5 instructions recommending 5min wash.

About 50% of the time the film comes out very neutral. About 40% of the time, the film has a very light pink/magenta cast to it that's only apparent when you lay the film on top of a neutral reference. About 10% of the time the film is pink enough that it's visible when you just hold the film up in the air and look through it. Once in a blue moon, the film has a light blue tint.

It does seem like there's a correlation between the amount of pink stain and how long the fixer has been used. TF-5 claims I should get 15-20 rolls (presumably meaning 1 135, 1 120, or 4 4x5) per 1L of working strength fixer. When I get to ~10 rolls it seems to be where I start seeing considerably more pink. This is somewhat of a problem given that I really would prefer to exhaust the fixer to make silver recovery with the Silver Magnet work properly.

So, my questions:

a) Does HP5+ have the problem discussed here?
b) Am I really exhausting the fixer that much quicker than the instructions say I should expect?
c) Is the pink stain appearing suggesting that the fixer is sufficiently exhausted to properly recover the silver?
d) Is it more effective (in eliminating the stain) to extend fixing or extend washing?
 
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Exhaustion refers to the fixing ability of the fixer. This is true for every fixer out there. The color stain may vary due to the brand or the particular size as for example 4x5 and 35mm are coated on different stocks.

A citric acid stop is NOT recommended if you have a retained color problem. Use of an acetic acid + sulfite stop is more suited, or a sulfite bath after fixing. The new dyes used in films can be rendered insoluble based on process and water supply. Acid, sulfite and other treatments such as peroxide will eliminate the dye. Time will also cause some of them to fade. OTOH, if they are uniform, they seem to cause no problem when printing.

PE
 

williaty

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Earlier in this thread, it was mentioned that the pink stain implies the presence of residual silver and that, even if the stain was even and caused no printing problems, you needed to remove it to ensure you had all the residual silver out. Is this true or can I just leave the pink and not care about it?

Does the citric acid stop just not help or does it make the problem worse? I'm using citric acid because the smell of acetic acid makes me sick. If the citric is not making the problem worse, I'll continue to use it. However, if it makes the pink dye harder to remove, I'll have to just switch to a water stop instead.

Someone gave me a 5lb jar of Sodium Sulfite from Photographer's Formulary. I've never had any clue what it's good for. If I kept my processing routine the same but added a sulfite bath between the fixer and the wash, what dilution should I use (in terms of g/L) and how long should I let it stew?

Thanks!
 
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Some colored materials can form salts with some acids. Citric acid is one of them. It is due to the solubility of the citrate salt and the molecular weight.

Sulfite is used to enhance removal of residual hypo from films and papers and it also reacts with some dyes.

The pink stain is NOT related to retained silver, but to reassure yourself, use the retained hypo kit and the retained silver kit available from several sources.

Many of your questions are quite basic and suggest that you should do a bit of reading up on processing films and papers before you have a problem.

Acetic Acid is vinegar. It is used at about 2% whereas many vinegars are sold at up to 5%. Don't try mixing acid with Sulfite or you really will have a smell that you don't like. Go careful and easy in this.

PE
 
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