Fogging - what caused this?

[butterfly]

Hello everyone,

I shot 4 images on 4x5 about two weeks apart, and then loaded them up into a combi-plan tank. I then left the tank on top of my refridgerator/freezer for 3 weeks before processing.

I've not suffered any light leaks before. The chemicals were all fresh and mixed correctly. I've checked the camera bellows for light leaks and the Kodak (latest type) readyload holder seems fine.

I shot an indoor image last night and processed it immediately and it is fine.

Have a look at the scan. The borders look all grey and 'muddy' and overall the image seems to be fogged.

I am at a loss to establish how this happened. On the other images the fogging seems worse opposite the film notches, which seem to exclude any packet clip problem.

I am wondering if not processing them straight away would be a problem?? Normally I process straight away.

Any help appreciated.

Regards

Steve

[Vaughn]

What are the Combi tanks made of? If they are rubber or plastic, could they out-gas chemicals they have absorbed? Seems like the top of the fridge is not a good place to store film -- fridges put out a lot of heat, and it all rises up to the top...and the warmer the room temp, the more heat the fridge generates.

Vaughn

[ricksplace]

I have had this problem with 35mm amd 120 film I left in the tank for a while before processing. It could be that your darkroom is not quite light tight, could be some chemical residue in the tank, could be darkroom gnomes. I really have no idea why it happens, but it does. So I always process the film right after the tank is loaded. Just another of life's unsolved mysteries.

[butterfly]

Thanks for the replies. Darkoom gnomes, he, he. Hadn't thought of that one.

Seems I haven't exhausted the list of ways to screw up large format yet :-(

Bank holiday looming, some tests are in order!

Steve

[butterfly]

Update: shot 2 images on two different readyload holders in daylight - developed straight away - both perfect! A chemist at the place I work (pharmaceutical) told me the tank would outgas enough to fog film in the period I left it. It is plastic with a rubber top. Won't do that again!

[Vaughn]

Hey, I guessed good:o

Vaughn

[eric]

Update: shot 2 images on two different readyload holders in daylight - developed straight away - both perfect! A chemist at the place I work (pharmaceutical) told me the tank would outgas enough to fog film in the period I left it. It is plastic with a rubber top. Won't do that again!

That's interesting! Never heard it before. Learn something new every day on Apug. Guess that's why SS tanks are the standard.

[Photo Engineer]

If they are bakelite plastic, they could release formaldehyde gas which will fog film. However, most other plastics will not easily release gas unless the carbon or other blackening agent used was contamnated chemically.

PE

[PHOTOTONE]

One should never leave film in any sort of developing tank, unless one is developing the film. Store exposed sheet film in the original film boxes, with a rubber band around it and clearly labeled EXPOSED-NOT PROCESSED.