Bleaching Pyro negs- need advice : LUSENET : Large format photography : One Thread

Some time ago I saw a post about this subject and could not find it in the archives. When I first started tray developing 8x10 negs in PMK Pyro, I was having some problems with the negs sticking together, and either getting a "static charge" exposure when I spearated the negs or part of the emulsion was torn. However it got there, I want to remove it. This is an area of the neg which is totally clear (except for the defect) ie film base + pyro stain. I know if I bleach out the defect that the stain will go also. I do not think that this will matter as in the final print this area will be black-no detail. I have a couple of negs to experiment with, and was planning to do the following: Re-wet the negative, and apply 10% ferri (in hypo) and bleach as you would a print (with running water). Once the "defect" is bleached out, I would re-fix (maybe with hardener) and wash. I know that this is "gorrila" darkroom work, but I want to save the neg and do not feel that scans and computers can reproduce 8x10 neg quailty, (even if they can there is a cost issue) Any suggestions about my quest??? thanks Richard

-- Richard (, March 06, 1999


I've never tried bleaching a neg. although to me it sounds like VERY risky business. You'll most likely lose your valuable pyro stain in this process which will make your neg. really thin.

-- Brian Jefferis (, March 06, 1999.

hello I already bleach some of my pyro neg . there no problem with them they keep their pyro stain. just take care to not over bleach to keep enough silver. Your neg will look really yellow as bleach add a little yellow color. no need to hardened the neg after. nze christian

-- nze christian (, March 07, 1999.

Don't do it!! If you are thinking about bleaching your pmk pyro negs be aware be very aware. Unless you are able to control your bleach solution you will get mottled and muddy areas. I have tried both types of bleach and had more success with farmers reducer and a spotting brush. The pyro stain will come off but you can stick your neg back in the pyro or just add some old pmk developer back on to the neg using a brush or sponge and let it set for a bit. Keep the pyro moving until the green stain comes back on. If you don't want to re develop the neg your stain will become yellowish and may or may not be noticeable on your print (depends on where it is.) I understand you wanting to save your negative but the success ratio has to be pretty slim. You may want to think about masking your negative so bleach doesn't get onto the areas you are not bleaching. How about asking Gordon Hutchings for advice? I am sure he has at least tried this before. I don't think it would be necessary to re-fix using hardner. Normal fixing should be fine. Once I tried using the pens from spottone to get rid of a defect on a neg and they worked ok but it wasn't a pyro neg. I wouldn't under any circumstances use the same method of bleaching that you wuld on a print. Because you won't be able to react quickly enough with a negative to stop the bleaching action. Even Farmers reducer reacts fast with a pyro neg. I'll get off my soap box so good luck and keep me posted.

-- jacque staskon (, March 07, 1999.

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