reversal 2nd dev fog

[holmburgers]

Call me out if I'm wrong, but isn't it a well established fact that you need to clear dichromate with sulfite and permanganate with bi/metabisulfite?

It just seems to me that the easiest answer is usually right, and this seems like a glaring fault to me.

Then again, why would the clear have anything to do with removing residual metallic silver? It just clears the bleach solution, which has ideally already done the job of clearing the silver. So who knows...

[Hexavalent]

I would think metabisulfite should work - it's the standard clearing agent for carbon-transfer and gum work.

[Nicholas Lindan]

Ah, just noticed - S. Metabisulfite is recommended for the clearing bath if you are using Permanganate/Sulfite bleach. S. Sulfite is recommended for the clearing batch if you use P. Dichromate/Sulfuric Acid bleach.

Though it seems the problem when using Metabisulfite with Dichromate bleach has been reported as loss of image, and not fog.

I've not tried Dichromate with Metabisulfite, but Dichromate works perfectly with Sulfite. The problem could be with pH: Sulfite is alkaline, Metabisulfate & Bisulfate are acidic.

[mrred]

Then I am on the mark and have nothing to worry about, except my dufus move on a clearing agent..... I did a full exposure frame on my MF roll before I did this one. It was as it should be.

[dr5chrome]

sodium metbisulfite & sodium sulfite can both be used as clear agents - it doesn't matter what bleach you use. Each has it's better use depending on the overall recipe and procedure. Both will do the job. Neither is an error.

regards.

[johnielvis]

sounds to me like it's not complete first development....if you put in second developer and it gets DARKER, then you didn't develop enough silver to have the bleach take it all away....OR incomplete bleaching, like has been said

you need NO clearing bath with dichromate--if you are patient....you CAN just keep rinsing and rinsing...that will get the dichromate out....permanganate...I dunno...that stuff really stains...

ACTUAL fog will show up in the transparencies as loss of Dmax and not darkness...it will be the opposite of darkness in the dark areas that were NOT exposed.

old film, for example, has more fog--you develop that like fresh film and you develop some fog to silver...this gets bleached OUT...then when you re-develop, there is less silver to re-develop, leaving less Dmax....so if it's too dark, it is NOT fog.

[Nicholas Lindan]

sodium metbisulfite & sodium sulfite ... Each has it's better use depending on the overall recipe and procedure...

Yes, that was the point - it seemed to be that the 'better use' was linked to the type of bleach, at least according to Kodak and Ilford literature.

Can you elaborate more on 'better use'?

[holmburgers]

sodium metbisulfite & sodium sulfite can both be used as clear agents - it doesn't matter what bleach you use. Each has it's better use depending on the overall recipe and procedure. Both will do the job. Neither is an error.

regards.

I stand corrected and willfully bow out....