Emulsion defect?

Fresh and different developer would seem to push the blame elsewhere.

The only way I can see the fixer being to blame is through overuse. It's possible to get fixer so oversaturated with silver that it deposits out easily, and maybe onto 'seed' sites in the film. The fixer would have to have been used to death though, and probably also stored in a well-used state.

I seem to remember that sodium/potassium thiocyanate can cause physical development to take place. Physical development is the deposition of dissolved silver onto a latent image - or any contaminant that provokes it.

My guess is still that something has contaminated the film or water supply. Have you tried bought distilled water to make up your solutions? Checked the camera for any possibility of depositing something on the film?

Fresh and different developer would seem to push the blame elsewhere.

 

The only way I can see the fixer being to blame is through overuse. It's possible to get fixer so oversaturated with silver that it deposits out easily, and maybe onto 'seed' sites in the film. The fixer would have to have been used to death though, and probably also stored in a well-used state.

 

I seem to remember that sodium/potassium thiocyanate can cause physical development to take place. Physical development is the deposition of dissolved silver onto a latent image - or any contaminant that provokes it.

 

My guess is still that something has contaminated the film or water supply. Have you tried bought distilled water to make up your solutions? Checked the camera for any possibility of depositing something on the film?

Thanks for reply. I have had these spots with two different developers, both freshly made up, so I can't see how it is the developer. Also, with three different films, FP4 in 35mm and in 120, and Rollei RPX100, so it can't be the film. The fixer seems to be the only likely culprit, other than my processing, but I've not changed at all the way I do this, and have not had such spots in 20 years of doing this.

My water comes out the tap, but gets there through chalk aquifer, and I reckon is some of the best water in the World. I'm sure there is no significant variation in water quality or chemistry. I have never used distilled water for the solutions before (other than final rinse). Each film was shot using a different camera, so that is not to blame.

I have another, fresh and unopened bottle of fixer, so next time I develop, I'll use that and see what I get. If that doesn't solve it, I'll take up golf!

so hows your swing coming along?

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