K12 Film - What's the difference from K-14 / where to process
This is actually a quesiton form a friend of mine-
he has a roll of old (probably 1940s) Kodachrome sitting about that was shot when it was new but is as of yet undeveloped. I'm fiarly sure that this CANNOT be processing in the K-14 process of today. If so, where can this be processed relatively inexpensively, or can it be done at home in a (modified) B&W neg. or reversal process? Rocky Mountain photo, I notice, will process it, but their price is, as usual, rather high ...
Also, my question, if the processes are indeed not interchangeable, what exactly are the differences between K12 & K14?
I'm fairly sure that K-12 can only be processed as B&W neg at this point. If you send it to Rocky Mountain Photo, I think this is what they do with it. You'll end up with B&W negs.
It's not possible to process either K-12 or K-14 film at home. Both processes are far too complicated and require automated equipment. For example, the color couplers are not present in these films and must be added during processing. The best that could be done is to develop it as B&W negative film and see if there are any images.
Thanks for the suggestions, they seem like good ones.
And as to the inability to process k14 / k14 at home, I'm certainly aware of it. Between the temperature control, the re-exposure steps involving perfectly filtered red, blue and white light, and the couplers, I realized that it was probably unlikely. I'm sure its possible, perhaps with careful control and the use of chromogenic toners for the couplers (actually, I recall reading an article about chromogenic toning on the Pure Silver List about a year back, which, IIRC, was posted by Gerald ...) Though the word "impractical" comes to mind.
Anyway, I'll see about processing it as a B&W negative. And, by the way, does K-12 have the Rem-Jet backing? I certainly don't want to goo my developing tank up with the Rem-jet paste by accident.
The old Kodachrome processes were designed for Kodachrome films with the old style hardeners, and therefore were run at low temperature or had a prehardener step with neutralizer much like E3/E4 did. The oldest process was more like E1. The current process is more like E6 in temperature and process cycle but as you note all Kodachrome processes use 3 color developers. I have posted the current process cycle for Kodachrome elsewhere.
It is possible to develop any Kodachrome film at home by hand given the formulas and couplers, it is just labor intensive and exacting. It was regularly processed by hand in the Kodak research labs, as there was no other way to process the small amounts of experimental coating we sometimes made up. When the process was the varaible in the experiment, it was often necessary to work with 1 liter or less of a particular processing solution if a chemical was only available in limited supply.
With determination, it would be possible to process any variant of Kodachrome or any other color film today to give a color image. I would question the results though due to keeping. Color films, on average, keep less well than B&W films, especially the older varieties before about 1970. This is not necessarily true of Kodachrome, as the extra coupling chemistry is not present in it and this has been one of the problem areas, but some variants of Kodachrome have been known to keep poorly for a variety of reasons.
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Thanks for the info, PE. I am aware that old films, if developed in color, would not keep terribly, well, though this would not be an issue. Any old color materials that I have / have developed are transferred to I computer as soon as possible. With Kodachrome, in keeping with the slide film nature, I'd probably find a way to make slide copies of it onto modern (E6) film.
I actually have a copy of the K-14 process cycle; it's quite intersting, but more exacting than anything that I've yet seen ...
It would be easy to determine by taking a piece of the film leader and looking at it. Rem-Jet would be a definite black. I've processed such film and waited until the end of processing to remove the coating using a sponge. The coating material decomposes in alkaline solutions leaving only finely divided carbon. The is nothing to gum up tanks or reels just wash everthing thoroughly.
Originally Posted by htmlguru4242
Kodak PB-2 to remove Rem-Jet coating.
Distilled water (50°C) .......................................... 750 ml
Borax (deca) .................................................. ... 20.0 g
Sodium sulfate .................................................. . 100 g
Sodium hydroxide ............................................... 1.0 g
Distilled water to make ........................................ 1.0 l
Originally Posted by Gerald Koch
Gerald, you have it essentially correct except for one thing.
The rem jet carbon, if left in place throughout the process can begin to accumulate in the developer and get depositied on the emulssion side of the film. Then, during drydown it becomes trapped in the gelatin and leaves permanent black 'dots' in the transparency.
You can do it as you describe but you must be super careful about 'dislodging' the carbon particles. Our method was to wet a sponge in water and then squeeze nearly dry and wipe the film front and back after the rem-jet removal step first in the process. Then, a thorough rinse, and then the process. Otherwise a fair risk of 'black dot'. Our supervisors didn't like that as it messed up the granularity experiments by introducing 'grain'.
Of course, if you are a pirate and get one of those black dots on a page from the Bible, then things take on an entirely new meaning. Heh. I think a few guys with a bad 'black dot' problem in their processes may have moved their supervisors to send them a page from the Bible with a black dot.