Can fixer cause film fog?

[percepts]

is it possible for fixer to contribute to film fog?

[MIke Sherck]

Sure. Contaminated fixer is the cause of what's commonly termed "dichroic fog".

[percepts]

Sure. Contaminated fixer is the cause of what's commonly termed "dichroic fog".

I don't think my fixer is contaminated but it may have been standing around too long and there is some precipitation in it. That may be the problem as I noticed fog raised from around 0.15 to around 0.3. Ilford Hypam

[MIke Sherck]

Easy way to tell: mix up some fresh and see if that fixes the problem.

[percepts]

Easy way to tell: mix up some fresh and see if that fixes the problem.

I hope that pun wasn't intentional

[Robert Hughes]

I hope that pun wasn't intentional

The "fixer" story: Back in the 1830's, Talbot was puzzling over how to keep his experiments from getting wrecked from light during viewing of his pictures. His friend John Herschel, the chemist, borrowed one of his freshly developed paper negatives and soaked it in sodium hyposulfite, as it was then known, returning it to Talbot, saying, "That should fix it!"

(A slightly more authoritative version is here - Wiki)
"He discovered sodium thiosulfate to be a solvent of silver halides in 1819, and informed Talbot and Daguerre of his discovery that this "hyposulphite of soda" ("hypo") could be used as a photographic fixer, to "fix" pictures and make them permanent, after experimentally applying it thus in 1839."

[MIke Sherck]

I hope that pun wasn't intentional

I've been accused of being subversive. Yes.