Varying base/fog densities caused by...?

Soeren · Mar 20, 2007

I was looking through my negs yesterday and stumpled over this odness. I have had some negs developed by a lab, some by a friend and som I did myself. The base densities differ. Some negs are almost clear in the rim some are grey and those developed by the lab are pinkish. I understand that the fixing has something to do with the pinkish base but what about the higher densities. Developer? fix? ageing? temperature? The developers I know of are Diafine, Rodinal, R09 and another twobath developer. The lab probably used D76 or ?? Films in question are Neopan 400 and Pan F+ both in 120 format. Fresh film is store in a freezer and moved to the fridge prior to use. Exposed film is stored in the fridge and the oldest exposed ine is aprox 6 month postexposure though it doesn't seem to differ from the latest which is about two weeks.
Cheers
Søren

phaedrus · Mar 20, 2007

As I experience it with 4x5 film (Acros as well as thicker emulsion Forte film) a pinkish base is an indication of not having watered the film enough. The pink dye (? reaction product?) actually comes out with the first few water exchanges. A fogged base can be caused by exhausted developer, old film, X-rays or even actual fogging by low light intensities as the film is handled before developing.

Roger Hicks · Mar 20, 2007

Soeren said:
I was looking through my negs yesterday and stumpled over this odness. I have had some negs developed by a lab, some by a friend and som I did myself. The base densities differ. Some negs are almost clear in the rim some are grey and those developed by the lab are pinkish. I understand that the fixing has something to do with the pinkish base but what about the higher densities. Developer? fix? ageing? temperature? The developers I know of are Diafine, Rodinal, R09 and another twobath developer. The lab probably used D76 or ?? Films in question are Neopan 400 and Pan F+ both in 120 format. Fresh film is store in a freezer and moved to the fridge prior to use. Exposed film is stored in the fridge and the oldest exposed ine is aprox 6 month postexposure though it doesn't seem to differ from the latest which is about two weeks.
Cheers
Søren

Dear Soeren,

Grey = fog, probably an unsuitable developer (some devs give much higher fog levels than others, varying from film to film). At least some types of Neopan are, IIRC, loaded with development accelerators and this may be relevant.

Pink = sensitizing dye, which is actually bleached by light: leave your negs in the light in a transparent/translucent sleeve for a day or two and it will go away.

Cheers,

R.

Soeren · Mar 21, 2007

Roger Hicks said:
Dear Soeren,

Grey = fog, probably an unsuitable developer (some devs give much higher fog levels than others, varying from film to film). At least some types of Neopan are, IIRC, loaded with development accelerators and this may be relevant.

Pink = sensitizing dye, which is actually bleached by light: leave your negs in the light in a transparent/translucent sleeve for a day or two and it will go away.

Cheers,

R.

Dear Roger
I didn't know about acelerators in filmemulsions. Fog fog is not severe but its there and its even over the hole film i.e. no streaks or spots so you are probably right. The Neopans where developed in Diafine so the acelerator could do some nasty things during bath A if its there. How much should I put up with? Yes I know its imposible to answer that since that must depend on ease of printing (contrast) but have a shot at it anyway. How about the Rodinal? Any experienced increased density/fog in Ilford films with that?
Cheers
Søren

j-fr · Mar 21, 2007

Soeren said:
Films in question are Neopan 400 and Pan F+ both in 120 format.
Cheers
Søren

Fog - or rather base + fog - differs with film type. Slow film (like Pan F) low b + f, fast films (like Neopan 400) higher b + f. And if the film is pushed the b + f goes up.

j-fr

www.j-fr.dk

PS: Tak for dine venlige ord i galleriet for snart længe siden - jeg skulle have svaret allerede den gang, men her var der så en anledning.

Soeren · Mar 21, 2007

j-fr said:
Fog - or rather base + fog - differs with film type. Slow film (like Pan F) low b + f, fast films (like Neopan 400) higher b + f. And if the film is pushed the b + f goes up.

j-fr

www.j-fr.dk

PS: Tak for dine venlige ord i galleriet for snart længe siden - jeg skulle have svaret allerede den gang, men her var der så en anledning.

Tak Jens
Hvor er i øvrigt den "Tunnel vest for Valby station"?
I have noticed the difference according to speed but didn't connect the two.
There is also a small difference between two Pan F+ films developed in Diafine and another dev. I recon I'll stick to Rodinal in the future.
Cheers
Søren

Roger Hicks · Mar 21, 2007

Dear Soeren,

Ilford doesn't recommend Rodinal with any of their films, as far as I recall -- low speed, big grain -- but it should work better with slower films, as others have indicated.

Fog isn't always a problem as you can often print through it, though the inevitable penalties are increased exposure times and (I would suspect) bigger grain and reduced sharpness.

And yes, I'd expect development accelerators to be bad news with two-bath developers but I've never really investigated the matter.

Sorry I can't be more help.

Cheers,

R.

Varying base/fog densities caused by...?

Soeren

phaedrus

Roger Hicks

Soeren

j-fr

Soeren

Roger Hicks

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