Negatives turning brown

[LarsAC]

Hi APUGers,

a few of my last negatives seem to turn brownish - and this is only 4-6 weeks after developing them. I tried to capture the problem on the light table, hope you can see what I mean.

Any idea what might cause this ? My process is Pyrocat-MC (normal agitation), water as stop bath, Adofix, about 6 changes of water per Ilford scheme, Adostab (Sistan) as final step. So far this has not caused any trouble.

For this batch of negatives I recognized that they would not really dry - like if they had some oil film on them on the base side. Hence I washed them again - but I have no clue if this is the cause (but stopped using Adostab for now).

Any ideas what might cause this ? Should I refix ? Other ideas ?

Lars

 

[Gerald C Koch]

Some people have experienced difficulties with the lfordd washing method. It is really short compared to conventional washing. Try fixing and rewashing followed by the Sistan.

 

[bdial]

Is the fix used for this roll fresh? If not, did you test its activity?

 

[chip j]

I have heard of problems w/Sistan.

 

[Svenedin]

I have not used Adostab on film but I have used it on prints. It will cause stains if the fixing is inadequate. It will also leave brown marks if the prints are not wiped of excess. I wipe the prints with a sponge. Something similar may be happening with your films.

 

[RauschenOderKorn]

Option 1: Film turning brown usually is a sign of incomplete fixing. I would try washing (to remove any sistan left), refixing with a fresh fixer and rewashing.
Option 2: This might happen due to the use of Adostab. According to the Adox homepage, Adostab is a Toner which migth intensify "existing problems". So it can be expected to react with residual fixer in the emulsion. An oily film on the base side indicates that probably there has been some problem with the use of the Adostab. Did you dillute it according to instructions and use demineralized water? Probably a higher dillution (more water, less Adostab concentrate) might be a good idea.

Adostab according to the label is based on the Agfa sistan formula, only more concentrated. Agfa on the other hand warned that a too high concentration of Sistan might produce stains and recommended wiping the negatives prior to drying:

source: http://www.maco-photo.de/files/images/agfa_Chemie_Film_gb.pdf

 

[LarsAC]

Thanks - will rewash, remix (with fresh fixer) and wash again. I guess, I'll try without Adostab / Sistan this time.

Lars

 

[Bill Burk]

I had yellow middles of 35mm rolls recently when I mixed the fix too weak. After refixing the color went away.

My thought looking at the negative, it sure looks like mine did. And I knew I was pushing my luck.

Remember the old adage: fix for twice the time it takes the negative to clear. That could keep you out of this kind of trouble.

 

[LarsAC]

Thanks for all the answers. I started to re-fix the films in question and things seem to improve (but I am still suspicious). Somewhat tedious as I had already cut the film into strips for filing ...

Lars

 

[Svenedin]

Glad there has been some improvement. After occasional problems with prints treated with Adostab (brown marks from not wiping off all the excess) I would personally not want to use it on films and I would question whether it is really necessary.