Uneven marks / deposit on film - hand processed - Paterson tanks.

[Tom Kershaw]

Recently I've processed a few films through Paterson tanks as one-offs - the vast majority of my film goes through the Jobo without issue. Here is a roll of expired ILFORD SFX - I've not seen these marks before and will do some experimentation as I'm curious to the cause - my first thought is something fixer related but these marking seem more like a deposit and don't look like fixer issues I've had in the past.

Any ideas?

 

[Sal Santamaura]

Lately I've had what look like similar deposits, although they're more blobs than the somewhat river-like shapes in your attachment, along with multiiple small scratches, on the base side of Ilford sheet films developed in Jobo Expert drums. Older Ilford sheet films, as well as Kodak and Bergger products, exhibit no such anomalies. I suspect Ilford changed something about the back coating.

My solution has been to avoid Ilford film. Bergger Pancro 400 in sheets and ACROS II in rolls are serving me well as alternatives, both exhibiting perfectly clean and defect-free bases after processing.

 

[MattKing]

Looks like incomplete fixing to me.

 

[Tom Kershaw]

I have now tried re-fixing in fresh solution and the markings are still there.

 

[MattKing]

I have now tried re-fixing in fresh solution and the markings are still there.

Are you using the same fixer you used before? Perhaps it is near exhaustion.
It might also be dichroic fog.

 

[Tom Kershaw]

Are you using the same fixer you used before? Perhaps it is near exhaustion.
It might also be dichroic fog.

I dumped the old batch and used fresh new stock Tetenal Superfix Plus diluted 1+4.

 

[MattKing]

I dumped the old batch and used fresh new stock Tetenal Superfix Plus diluted 1+4.

Then I lean toward dichroic fog, which I have rarely seen.
Were you using replenished X-Tol?

 

[Tom Kershaw]

Then I lean toward dichroic fog, which I have rarely seen.
Were you using replenished X-Tol?

I was using T-Max developer as I had a time listed for the SFX film. Thinking about it, the Kodak developer does warn about dichroic fog, but I thought that this applied towards sheet film.

 

[MattKing]

I was using T-Max developer as I had a time listed for the SFX film. Thinking about it, the Kodak developer does warn about dichroic fog, but I thought that this applied towards sheet film.

It does.
I do note though that Ilford's data sheet does provide a developing time for T-Max developer.
I have a vague recollection of reading that the 120 SFX is, unusually, on the same film base as the sheet film, but I can't find any confirmation of that, so my memory may be wrong.

 

[Tom Kershaw]

It does.
I do note though that Ilford's data sheet does provide a developing time for T-Max developer.
I have a vague recollection of reading that the 120 SFX is, unusually, on the same film base as the sheet film, but I can't find any confirmation of that, so my memory may be wrong.

I didn't realise ILFORD made a sheet film version of SFX at some point. As a point of reference I processed a roll of Delta 100 in a Paterson tank earlier this evening using XTOL replenished and did not experience the fogging / stain.

 

[Ian Grant]

SFX is related to an Ilford Traffic film designed for speed cameras which is (or was) an unbacked roll film, so a base more like 220.

Tom, the fixer had gone almost neutral or alkali and was near exhaustion Dichroic fog is a strong possibility, sometimes quite strong fixer will clear it but too long will act as a reducer. I used to see it occasionally but with experimental work, mostly with monobaths. Ron Mowrey (PE) said he'd seen it with Alkali fixers where a stop-bath wasn't used.

Ian

 

[Tom Kershaw]

Tom, the fixer had gone almost neutral or alkali and was near exhaustion Dichroic fog is a strong possibility, sometimes quite strong fixer will clear it but too long will act as a reducer. I used to see it occasionally but with experimental work, mostly with monobaths. Ron Mowrey (PE) said he'd seen it with Alkali fixers where a stop-bath wasn't used.

I tend to be generous in replenishing my batches of film fixer so I must have forgotten to do so. I use a stop bath, usually and currently the Kodak indicator product.

 

[Tom Kershaw]

Preliminary results indicate the T-Max developer may be at fault (or some sort of chemical interaction). The developer concentrate is expired - half full original container - but activity level seems fine, possibly exposure to oxygen has had some effect? - Ian would be much better placed to comment on this than I am. Oddly I now realise that some of the deposit can be wiped off to a certain extent with fingers.

 

[Tom Kershaw]

results with fresh fixer:

Film	Process method	Developer	Result
Delta 100	Paterson tank - inv	XTOL-R	good
SFX 200	Paterson tank - inv	XTOL-R	good
Kodak Plus-X	Jobo CPP-3	XTOL-R	good
Kodak Plus-X	Jobo CPP-3	Kodak T-Max	marks / staining

Conclusion: Exercise caution with out-of-date Kodak T-Max developer even though activity is fine and appearance of the concentrate gives no cause for concern. As far as I can tell process method does not impact on formation of the staining / marks / deposit.