Processing E-6 film as B&W and bleach out the silver color filter BEFORE developing?
I have tried to develop E-6 film as b&w, but it results in dark dense images due to the collodial silver color filter in the film.
When making b&w slides, you develop, bleach out the developed silver, rexpose and develop again.
This bleach used in this process does not attack the undeveloped silver bromide in the film. Just the silver.
What if I use this bleach BEFORE developing the exposed film.
1: Will it bleach out the collodial silver in the film?
2: Will it attack the latent image and destroy it, or will it survive and can be developed afterwards?
I'm curious to know the answer to this as well.
The layer of Carey Lea Silver that acts as the yellow filter behind the front/blue sensitive layer; is it already "silver" in the same sense that developed silver-bromide becomes silver? In that case, why isn't it coming out with the bleach regardless of where it is in the processing steps? How long are you bleaching for?
Although it doesn't seem like bleaching before the 1st developer would harm anything, since there's no silver image yet, it also doesn't make sense to me why the CLS would become unbleachable after that dev'er.
Hopefully others will join in... I honestly have no idea but wanted to at least bump the thread.
When developing as a b&w film, there is no bleach in acton.
Originally Posted by holmburgers
Developer, stop, fix.
Since there is no bleach, the color filter is still there.
So, I have to choose. Develop as a positive film, OR bleach out the silver color filter before developing.
If I develop as a positive film, the proces is as this: Developer, stop, bleach, clear, re-expose, develop, stop and fix if neccesary. Washing is always neccessary.
But, this gives a positive flm. That isn't directly useable in the darkroom.
If I can bleach out the silver color filter before developing, the rest is just as developing a b&w film, resulting in a negative film.
My mistake, I thought you were already developing it as a positive.
But why do you need to bleach before developing? The CLS, if I'm not mistaken (which is of course possible), should not become developable. I don't know if it has any sensitivity, and if it did, it would be so much slower than the primary emulsion that it wouldn't be affected by developing agents.
So if that's the case, just like in C-41 processing, you could do the bleach after development.
Am I off base?
CLS? What? I don't understand.
Originally Posted by holmburgers
Developing with b&w develper and bleaching will remove ALL developed silver, including the developed image. That's not a good idea :-)
It can be re-exposed with white light and developed as a positive image, but that is not what I want.
The collodial silver color filter IS silver before developing, so it can be bleached before developing, but what about the latent image? Will that be present after bleaching? Remember that this bleach doesn't bleach undeveloped parts of the emulsion.
I guess I have to shoot a film and try this to make sure if it works or not.
If it works, I have a method for using old ektachrome films, and also a way to use old kodachrome films.
Just add some alkali and dishwashing detergent to a bath between bleach and developer to remove the rem-jet layer.
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Colloidal silver = CLS (Carey Lea Silver) = yellow filter layer.
Ok, ok, I think I get it now. Absolutely you're right... this bleach (permanganate/dichromate) will destroy a developed image (duh, what was I thinking...), and by that same logic it might rid you of the colloidal silver.
In that case, it sounds like it might work.
As for the latent image, you'll have to test it, which it sounds like you plan to do. The "printing out" emulsions of old however required only exposure to create metallic silver (or is that not entirely accurate?), and so it makes you wonder if your latent image will be safe.
I wish I could be a bit more concrete in my offerings here, but it's an interesting question and I wanted to take a stab at it. Surely there are others who will be able to give better evidence, but they seem to be lurking in the shadows tonight...
Yeah I'm intereseted in this too, a few bricks of KC might be coming my way.....
The Permanganate or Dichromeate bleaches used in reversal B&W processing will bleach out the latent image and dissolve it!
Well, that was exactly what I was afraid of.
Originally Posted by Photo Engineer
This is a dead end then.
But I have to test this anyway.
To make a simple and cheap test, I am goung to ask someone with an interest in aquariums to get a small amount of permanganate (used to kill parasites on fish) and mix up a small amount and dip an exposed leader in it for some minutes and develop it afterwards. I have to do that in the dark to avoid re-exposing it during development. If it don't get black, you are right about this, which I suppose you are, but if it gets black, there is still hope.
Do you have any other trick up your sleeve to get rid of the collodial silver without making a positive, or destroying the images.
Doing it the hard way would be as this:
Bleach in darkness,
respooling the film, still in darkness.
Exposing the film as normal and devlop as a b&w film.
You are not afrait of work, my friend.............