E4 film and hardening
I guess this is most likely directed to Photo Engineer but here goes:
I have a 5"x100' of Aerial MS Ektachrome from 1974. The film itself has survived all those years with grace, it can be exposed at 50ISO and developed into a negative without much problem. As you can guess, the emulsion will partially come off the substrate when ran through E6 - what survives are cyan highlights and a dash of magenta. Yellow floats off completely. And doing room temperature C41 (or ECN2 in my case) still results in a soft emulsion that is extremely easy to damage while wet. Even agitating the developer seems to cause damage.
Now, I experimented with 10ml of 37% formalin and 25g of soda ash dissolved in a liter of water (didn't have the sodium sulphate at hand), that hardened the emulsion plenty BUT as some of you may know, that ties up the magenta coupler, so no magenta dye is formed during development. I have studied the E4 formulas (here: http://www.kodak.com/global/en/profe...111/cis111.pdf) for quite a bit now and I see that the aldehyde must be neutralized before the development and the hardening is done in an acidic environment.
My problem here is that I am short on cash most of the time and the process seems to rely on some specific chemicals (having a Kodak something something designation) and I am unable to mix up the right stuff. Could I theoretically make the goo I made earlier more acidic (acetic acid maybe?) and then neutralize it with it something more simple? It would be a shame to let that roll of film to waste, considering how well it has survived.
Thank you for your attention!
Let me preface this by saying that I don't know nearly as much about this as you do. That being said...
I acquired some E4 IR sheet film, and also have been wondering how to process. The consensus from discussions read in the archives here is that it should be possible to process them in E2 or E3 (E2 being far more common), since E4 is basically E2 with the neurotoxic reversal agent in place of the re-exposure.
However, I found a guy who processes E4 as negative with the C22 process. Much less toxic and less involved than either E2 or E4. So maybe that might be worth a try. Here's the link:
And here's a guy who does E2 film (that apparently could also be processed as E4) in a modified c41 process:
If you have either of these already, my apologies. Hope this helps, let me know how it all comes out!
Hmm, I could try just adding sodium sulphate but I have my doubts about it. The aero film is on tissue-thin base and that really does not help the emulsion peeling. Formaldehyde is irreplaceable for high temperature processing as I understand. And made neutral by Hydroxylamine Sulphate. I have the formaldehyde and I could get my hands on the HAS but I intend to skip some of the chemicals to keep the cost down which, I know, is a stupid thing to do. So I am trying to understand the workings of this process to make it as simple as possible.
Who knows, maybe the sulphate routine will work? Most likely not well enough that the film would survive E6 and end up as a positive but who knows.
The E3 1st Developer is relatively simple and then you use a Chrome Alum hardening stop-bath which is very effective.
E4 runs at a higher temperature than E3 so needs a pre-hardener, but E3 at 24º C is far more practical and you should be able to make up all the solutions quite easily. I used to make my own E3 occasionally later switching to E6.
I got this yesterday, 10 minutes in ECN2 soup at some 23 degrees Celsius. There is a lot of emulsion damage there actually, even from careful handling. And as said, the formalin pre-hardener works like a charm (even without the sulphate!) but ties up the magenta, so a cut from a roll ran through the chemicals resulted in turquoise color, instead of black.
Ian, the film is designed for EA-4 or EA-5. I am aware of the temperatures and it is meant to be processed in an AR-5 processor with EA-5 chemicals but with prehardener. AR-5 first developer runs at 49 degrees Celsius!
I thought of using cold B&W first developer as well, then hardening it after or during stop bath. Would you please elaborate on your chrome alum stop bath?
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IIRC, there is also Succinaldehyde Bisulfite adduct in this prehardener formula. This compound works like Formaldehyde but leaves the emulsion in a more swollen state. VPooler, your results seem to suggest that you need this compound in your prehardener.
Trying to be the best of whatever I am, even if what I am is no good.
Succinaldehyde was used to lower the amount of formalin put in the solution. Can be substituted with more formalin. I rummaged about in my shelves and found the venerable soviet-era photorecipe book which contained various formulas for hardeners. The formalin/succinaldehyde and the respective neutralizer can and will fog the film if not made properly so to answer my own question - it can't be made much simpler. And from what I heard, it emits a noxious gas when neutralized. I also remember PE from some post in another thread mentioning that he used chromium alum for some of his earlier color work.
Originally Posted by Rudeofus
Hardening stop bath, however, is made by mixing up the following:
Water (30-45 degrees Celsius) 500ml
Chromium alum 15g
Acetic Acid (28%) 14ml
Cold water to 1 liter
I found from the same book some advice on hardening the emulsion of both soviet and Orwo color materials. A lot of them are basic chromium alum solutions, sometimes with some boric acid or such added, only one contains formalin. So I am pretty confident. The content of chromium alum ranges from 10g to 20g per liter of water and should be discarded once the solution turns greenish. The chrome alum hardening is recommended for tropics, when the temperature reaches 25...30 degrees Celsius and it is claimed safe to use in this range as a pre-hardener. The recipe just calls 10g of chromium alum dissolved in a litre of water for pre-hardener, for using as a stop bath, the recipe is described above. Maybe cold (20 degrees) paper developer for 'bout 10 minutes, followed by hardening stop bath, a good wash and ECN2 at 38 degrees for 6 minutes IF the emulsion can withstand it. If not then 30 degrees and some 10-12 minutes. Might as well try pre-hardening with a strip.
Anyway, I got half a kilo of chrome alum off evilbay for some 20 of my European moneys, let's see how it works. I am excited as the film itself has survived the test of time with grace, I imagine I could rate it even 64ISO or maybe more as the 50ISO results were good, no fogging whatsoever.
The Chrome Alum hardening stop is the way to go. In fact, you could use a Chrome Alum prehardener (just 5% or 10% Chrome Alum in water, I've forgotten now). If you use any Chrome Alum bath, make sure there is a good wash afterwards.
Do not use Formalin, as it can tie up the magenta coupler and the Succinaldehyde requires a post treatment bath so forget these as well.
Allright! Thanks for confirming this! The chrome alum should reach me in a week or two, I'll toss a strip of film in a solution of it and see how it works out. I could've probably gotten awaywith regular room temperature processing but aero film is on such a thin base, it warps during agitation due to the turbulent flow.
Originally Posted by Photo Engineer
I already experienced Formalin messing up the magenta. Better leave it for the stabilizing bath!
But most importantly - I am very surprised to see that the film has no fog or anything whatsoever!
You've asked about E4 processing though , which was always inter-changeable with E3.
Originally Posted by VPooler
You can easily find the E3 formulae online with the chrome alum hardener. I have a few alternative E3 formulae in various books, and used one for a while.