Film Fogging Mystery...

[erikg]

Isnt Dichoric fog when chemicals carry over from the developer to the fixer? A stop bath prevents it

I've only personally seen it with replenishment systems with the fog happening in the developer regardless of stop bath used. This is basically why TMax RS developer was formulated, it was happening in labs using TMax Dev in deep tanks. You are probably also correct, and it probably doesn't apply in your case unless the fog has that rainbow color aspect to it. Best of luck, these things can be very vexing. At least you still have usable images.

 

[Nikanon]

Do you buy your film in rolls, or are you rolling your own from bulk film?

I buy either straight from Kodak or from Freestyle
Who bulk rolls Tri-x from Kodak as Arista Premium

 

[Nikanon]

The positives you posted aren't much help. How about scanning the negatives in their entirety, including the sprocket holes, so we can get a better idea.

Some other random thoughts:

How old is your film? Has it been stored/handled correctly.
Are you seeing flare from something instead of fogging? Low-level flare raises fb-f.
Is there a possibility that you haven't fixed properly? Try refixing a neg in fresh fix if you have any doubt.
Dichroic fog gives a rainbow-like effect when the neg is viewed in glancing light. Check (although that's likely not your problem).
Are you bulk loading? Check your loader and how the bulk rolls are stored.

Thinking basically, fog comes from light or chemicals. I rather think that light is your culprit here, especially if it doesn't affect the entire negative. Keep looking for the source; camera, loading, storing, transferring to reels, the tanks themselves, etc., etc. And good luck.

Doremus

Right, I'll try that next time I'm able to scan. Films range from two years to less than two months old, it's all handled and stored properly, usually it gets shot right away and stored
In a dark cool place or refrigerator if long enough from shooting to developing. I'm familiar with flare, and this is not that. I fix for 7 - 8 minutes, but prolonged fixing does nothing. I am not bulk loading. I believe the culprit is chemical based on the evenness of the density even between films (all 0.5 fb + f).

 

[Nikanon]

You need to address one variable at a time. I would start with where you load the reels to make sure it is absolutly light tight. Next, I would consider whether you are getting a proper fix, you are doing multiple reel tanks and may not be getting enough agitation to properly fix all film. Then lastly, you should rethink developer. My thoughts are that you are either getting fogged in the loading, or your agitation regime is not sufficient to completely clear film.

Another person used the same loading space and did not get the fog problem. I fix for 8 minutes, same fixer I have always used that typically clears the film in 3-4 minutes. Agitation is smooth and even with twisted inversions. Exact same scheme works for another persons Tri-x and this developer.

There are two big changes between my development and my
Friends.

1. His film did not fog
2. My film both did and did not fog

This says it is either the film itself, which it is not, the same film was fine in D76 or sprint, but it also cannot be the developer since it has been successful for him and myself but has fogged mine.

 

[mfohl]

When you finally solve your problem, please share the solution with us. This has turned out to be a real mystery.

 

[bobmolson]

fogged film

Fogged film


I fought fogged roll film for months until I stumbled on the answer. It had nothing to do with the camera or chemicals but the back of a sheet of fresh photo paper ,nice and clean, I was loading on. I have fluorescents in my darkroom and the UV was activating the paper brighteners and fogging the film as I loaded it onto the reels The clue was the fog followed the pattern of the reels. If you have a black light check for UV in the area you are loading the film.

 

[Rudeofus]

From looking at the MSDS (which lists Sodium Hydroxide and Muriatic Acid) I infer that Sodium Chloride is the "fine grain" component in FG-7, similar to Microdol (but not Microdol-X which contains a secret ingredient to fight dichroic fog! ). As it just so happens, Edwal sells a product called "Liquid Orthazite Concentrate Anti-Fog Agent" (which (there was a url link here which no longer exists) is Benzotriazole and Sodium Sulfite) ....