Experimentation: Color in B&W

[Mike Kennedy]

I am sacrificing the Kodachrome in the name of science.
Not a big fan of transparency film,especially outdated stuff, and the price was right $2.00. Figured what the heck?
Even colder today (-36c with wind chill) so the test is postponed.

Mike

 

[Donald Qualls]

Question: I reuse my fix & stop bath til near exhaustion. Would the chemical residue from processing color as B&W mess up my fix & stop?

AFAIK it has no effect on reused developer (I've used Diafine for this a couple times), stop bath, or fixer. The only thing that's in color film that's not in B&W is dye couplers and the filter layer; the dye couplers become the orange mask and are effectively inert except to the reaction products of color developer, while the filter layer is colloidal silver and is normally removed by the bleach step in color processes, but won't affect B&W chemistry.

 

[Donald Qualls]

I am sacrificing the Kodachrome in the name of science.

Kodachrome makes fine B&W negatives. You'll need to remove the remjet backing after processing, if it doesn't just pour off with the developer (Kodachrome is the only still film with remjet -- which *can* make your developer non-reusable if it comes off in that step). Plan on using a one-shot developer for Kodachrome. Any mild alkali and a little gentle wiping (like with a wet paper towel) will remove the remjet from the base side; I used a solution of 1 tsp washing soda in a pint of water the one time I've done this (a failure because the 40 year old film was shot in a camera with sticky shutter and was hopelessly fogged).

Kodachrome has a clear base, no orange mask, because there are no dye couplers in the film; it's essentially a three-layer B&W film that gets color due to the special, and very complex process it receives. There is a yellow filter layer, but that is made of silver grains so fine that mild overfixing in rapid fixer (call it a half hour) will remove the filter layer. The end result *should* be a very clear base with crisp, clean B&W negative images. I've got another roll here (came in a 40 year old camera, probably with major focus problems) that I'll be trying soon.

 

[Mike Kennedy]

Great follow up information Donald. I'll jot it down and include it in my development log.


Thanks,
Mike