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Discussion in 'B&W: Film, Paper, Chemistry' started by Photo Engineer, Nov 23, 2010.
Hypo Clearing Agent helps remove hypo. The pink or magenta stain is from silver not hypo.
Might as well ask...
For TMY-2, I use fresh (acid) fix, but no Hypo Clearing Agent.
When I first put sheet film in the wash, it makes the water noticeably pink. I transfer the film tray-to-tray filling and draining the wash water in my 5x7 inch trays (and the wash water is about 20-degrees C). At each transfer the tray I drain is less and less pink. In about 20 minutes the water I pour out is clear and that gives me confidence that I have rinsed out the dye.
Should I then continue to wash the film longer (perhaps wash for twice the time to clear)? Or (considering these are complete changes of water... seems like an effective wash) am I fairly clean after 20 minutes?
Use a retained hypo test solution and a retained silver test solution to get that information out of your film Bill.
Let's keep in mind that the pink stain has absolutely no negative effect on image quality.It's purely a cosmetic issue.get over it!
Well, if the stain is nonuniform or varies from film to film, it can affect VC papers!
But, what it does is give you higher speed at the same grain through either dye layering or 2e sensitization or both. And, it is easily removed.
I went back to some of my earlier TMX negatives (2005). I found several with the uneven pink stain. I did a refix for 7 minutes and rewashed and eliminated the stain. I have been more careful lately and now fix Tmx for 10 minutes and throw out my fixer more frequently . (Every 32 sheets of 4x5)
Unfortunately, I'd did find two (out of a or 250) with the pink stain that also had the tell tale sign of brown stains.
You cannot ignore the pink stain. Refix and rewash is the answer.
In fresh fixer...
And longer washes.
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.
Yea and I use HCA as well.
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.
Haven't you heard? This is all in your imagination because magenta is not a color.
It's a hue.
Get a clue.
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...
I have witnessed this as well with HP5 sheet film when I use Pyrocat-HD, but not when I use Rodinal.
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?
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?
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.
I doubt to leave, I use selenium toner rapid few minutes
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).
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?
Apparently, the Sulfite is what does the job. It seems to destroy the dye.