Reversal Processing: Re-exposure & fixing questions

[thefizz]

Re-exposure:
I have read some guidelines saying the re-exposure of the film is done before the bleaching stage and other guidelines saying to re-expose after bleaching. Does it make any difference if done before or after?

Fixing:
I know fixing should not be necessary but if doing so, does it matter if it is an acid or alkaline fix? The Darkroom Cookbook says to use an acid fix and not alkaline but the Foma kit comes with an alkaline fixer. Any reason why one should be better suited than the other for reversal processing?

 

[pdeeh]

You sound a bit confused.

Are you talking about black and white or colour reversal?

In the case of black and white, bleaching must be done before the re-exposure. If you do it afterwards you will have nice clear film.

In the case of colour, it can be done in either, but is usually done afterwards as part of the bleach-fix process.

What do you mean "fixing should not be necessary" ?

Fixing must be carried out after the second developer, otherwise you won't remove any unexposed or partially-exposed halides and your film will eventually fog.

 

[thefizz]

You sound a bit confused.

Are you talking about black and white or colour reversal?

In the case of black and white, bleaching must be done before the re-exposure. If you do it afterwards you will have nice clear film.

In the case of colour, it can be done in either, but is usually done afterwards as part of the bleach-fix process.

What do you mean "fixing should not be necessary" ?

Fixing must be carried out after the second developer, otherwise you won't remove any unexposed or partially-exposed halides and your film will eventually fog.

I'm talking about B&W reversal. When bleaching, re-exposing and redeveloping the film, there should be no further halide to be removed. Hence fixing is not necessary. But if one decided to fix anyway, just to be sure, which of the acid and alkaline fixers is best suited?

 

[pdeeh]

Fixing is "theoretically" not necessary, but I'd be extremely surprised if anyone who cares about their process doesn't fix after second development.

any fix will be as good as any other

 

[Rudeofus]

Since a bleach will remove latent image centers, I would reexpose after bleaching, not before. Also, there may be silver halide grains that are not developable even after reexposure, and these need to go away ---> fixer after second developer.

If you go directly from second developer to fixer, you carry over some developer present. That one minute wash suggested in the Darkroom Cookbook seems a tad short. Fixed out silver may react with developer and form dichroic fog. An acidic fixer will avoid this, but if you use a stop bath and/or a proper wash after the second developer step, you should be able to use any fixer.

 

[thefizz]

Thanks Rudeofus, I was just curious why the cookbook said not to use an alkaline fixer when that is what is in the Foma reversal kit.

Re-exposing before bleaching seemed strange to me but that's the way I seen it described by a few people.