Extended wash times for c-41/e-6 processing

[DanielStone]

hey all,

I've been mulling over this for the last week or so, trying to read on here, and other forums/sites to see if extending the wash time for my c-41 and e-6 films in order to increase archivability, and to make sure all residual chemistry is out of the film before drying and storage in archival materials.

since the 'proper' wash time for c-41 is 3:15 at 75f-105f, could I go longer than this, say, 6-10 min, would it affect the outcome and archivability of my film? same with e-6, deviating from the 'recommended' wash times.

thanks

-Dan

 

[Mike Wilde]

The archival issue for b&w is the silver image stablity. The archival issue for c-41 is dye image stability. For E-6 the same, but also get all the silver out to pevent darkening.

So for b&w fast fresh fixes (not too long) wash, HCA. wash. sistan, selenium etc.

For C-41 the issue is how processed. If home brew, wash well, and a final rinse with a few ml/L of formalin in with distilled water with not too much phtoto flo is the best bet, then to store them in acool dry place in compatible material.

For E-6 I have heard of adding a rinse between bleach and fix, to cut bleach carry over and keep the fixer happier. Then rinse again and do a second fixer to get the last residual silver. Wash well in running water.
If home brew E-6, then formalin in final rinse is still recommended.
If commercial 6 step E-6 , the pre bleach, CD carry over and bleach all combine to stablise the dye and formalin is not needed in the final rinse.

Somewhat longer than recommended wash in any colour process will not do any huge harm, but it will not in and of iteself enhance dye stability.

 

[DanielStone]

thanks Mike,

that's what I was looking to hear/read. Many thanks

-Dan

 

[Photo Engineer]

Wash should be such that there is no retained silver or hypo using the same tests as you would for B&W. The problem is that it is hard to see the color through the colored C41 mask. Therefore, you use some E6 film in C41 to give a clear strip with about the same silver content to start with and about the same thickness.

Normally, with a good wash, the final rinse should not discolor from carryover of fix or bleach. If the fix discolors from bleach carryover, then the first wash is not good enough either.

PE