BW reversal fail x2

[pkr1979]

Hi Thomas,

Do you re-expose using light?

Cheers
Peter

[Pere Casals]

Develop 2 HP5+ 24°C Jobo CPA2 75 rpm:

Sorry, I had not seen what you where using HP5+ with permanganate... this does not work !!! (at least to me)

While permanganate (usual formula) bleaching worked to me with several films, it not worked with HP5+, dichromate bleach instead worked perfectly with HP5+, but you know, dichromate has to be managed with proper care, as pointed in the other post:

https://www.largeformatphotography.i...=1#post1476647

[pkr1979]

I'm really keen to do this without having to do the re-exposure using light...

And Pere, your reply is pretty long. And encouraging :-) After last nights fail I was tempted to just drop the whole thing, bit I'll keep on trying this.
Slides are what I shoot for color film, so Im also really keen to be able to do black and white slides... to me there is just something very appealing about finishing the shot in the camera (as the process is predetermined and you get an original which is a finished photograph). Oh, by the way... the film I used was HP5+ (I wrote that at the top of the process steps list - its not that visible).

I had another look at the developed film from my 2 attempts (all HP5+)... and the 2 films from the first attempt looks like normal (pretty much) developed negative film, except they have streaks... does anyone know what may have caused this? I have never seen this when I have developed E6.

From my second attempt the film is almost transparent... but still negative... like underexposed negative film... still streaks. I think this is a bit weird as the only difference is a stronger bleach used for a longer period of time - or does this make sense? You might be right about potassium permanganate not being that great for HP5+... but Im not that comfortable using dichromate either as I make these solutions on the porch where my kids play. It should be possible with HP5+ and permanganate as well... I think...

[pkr1979]

Pere - I saw your new post just after I posted mine - do you know the difference on dichromate and permanganate? I mean, I assume dichromate is stronger... at the same time, this doesn't necessarily mean, I guess, that if one makes a stronger permanganate solution it will have the same effect as dichromate as it is 2 different chemicals?

[tgtaylor]

Hi Thomas,

Do you re-expose using light?

Cheers
Peter

Yes. If using D-11, just follow the directions set-out in the Cookbook substituting 3:1 for 1:3 for the given dilution and tweak the ISO according to your preference.

Thomas

[Pere Casals]

Pere - I saw your new post just after I posted mine - do you know the difference on dichromate and permanganate? I mean, I assume dichromate is stronger... at the same time, this doesn't necessarily mean, I guess, that if one makes a stronger permanganate solution it will have the same effect as dichromate as it is 2 different chemicals?

About changes in formulation, I only been diluting the bleach bath to deal with CMS 20, otherwise I've always used the usual exact formulas.

In general Dichromate is considered a better bleaching agent (not stronger or weaker...) because it selectively removes better the metallic silver and not the halide, but it has the toxicity drawback, that can be overcomed well with a careful handling. In fact it's used for carbon printing...

I that post I explained how to do all after 1st development with open lights, you may use that to see if the permanganate bath strength level has an effect. First just diagnose that bleaching is what is failing, in that way: if after development (and stop) you have the yellow with black stains then 1st development worked, so check with lights open what your bleach does...

If adjusted Permanganate strength does not work, then just get some potassium dichromate from ebay to test with it (with care!)...

...or just use a film that's known to work well with the permanganate bath, as TMX, here you have the Photographer's Formulary kit for TMX, using permanganate:
https://www.digitaltruth.com/products/photoformulary_tech/Reversal%20Process%20for%20T-Max%20[01-0600].pdf


You may find plenty information from reversal process for movies, some cinematography schools released plenty information to reverse Tri-X and TMX:

https://www.youtube.com/watch?v=aDhqsaoi4sg

See how they do all after 1st development with lights open. And they are masters about that !


Here you also have the reversal process for tri-x : https://www.freestylephoto.biz/stati...iXReversal.pdf

the important info in those datasheets is developer used and time, that's the complicated thing to adjust, bleaching has to be simply the suitable one. Regular dichromate formulas only failed to me with CMS 20.

Here you also have a caffenol formula (expand description under the video) with caffenol: https://www.youtube.com/watch?v=W103Tc_6FRk