Have you checked with any labs if they are capable and willing to do so? Keep in mind that most labs, at least for roll film formats, use automated processors (dip & dunk or roller transport) that technically cannot be manipulated to skip any processing step.i want to pre-dev my e-6 in bw (testing which bw trickery would yield the best result) and send to the lab to finish the color dev. They would, then, bypass the first bath in the process.
In both E6 and C41 the basic principle is the same: the color dyes (not pigments) are formed as a result of oxidized developer binding to the embedded dye parts in the emulsion. Hence, the colors are in essence a byproduct of developing the silver image. The silver image is in regular processing consecutively bleached and fixed away, leaving only the dyes. So if you mean this by 'needing the halides', then yes. You need exposed silver halides and a color developer whose oxidated remnants bind with the dyes in the film. This is true for all contemporary color materials: C41, E6 and RA4.as far as i understood for e-6 you need the halides, not the silver, to activate the pigments and the bw dev would have washed it out.
So if you mean this by 'needing the halides', then yes.
No, it doesn't work that way. The dyes (not pigments) are formed during development of silver halides into metallic developer by a color developer of the ppd family. The dyes are formed through combination of molecules in the emulsion and oxidation products of the color developer, which emerge as the result of the color developer developing silver halides into silver metal.fully dev&fix the film for a bw standardish negative (wouldnt even need to bleach) and handle to the lads at the lab: they put it in the machine, it tries to develop it for no avail (the halides are already washed at home) and keep the rest of the process. presto: negatives ready for printing.
(sound of gears working...)
Yes, essentially. The 'dye seed' as you call it are the dye couplers: colourless molecules that when combined with oxidized developer turn into the cyan, yellow and magenta dyes that make up the image. With B&W processing, these dye couplers remain embedded in the emulsion. So if you were to add oxidized color developer to the emulsion, the oxidized developer will combine with the couplers and create dyes, regardless if a silver image is present or not. One way of doing this is bleaching back an existing silver image and redevelop it using a color developer. This is what the AE-31 tech pub outlines: take a black-and-white processed color negative film, bleach back the silver image with a rehalogenating bleach so that the metallic silver is turned back into silver halides, then redevelop using C41 chemistry. In the C41 process, first the silver image is redeveloped creating oxidized CD4 as a byproduct which combines with the still present dye couplers to form the color image. Then the silver image is bleached and fixed in the further processing steps.regarding AE-31 statement: since the dye seed and the rest of the untouched dye are not washed away during bw fix the CD-4 of reprocessing it is able to further develop it back into colours.
Color positive film is in essence not all that different from color negative film: it has silver halides, color sensitizing dyes and dye couplers just like a color negative film. But in color positive film, it is not the initially in-camera exposed silver halide that is used to create the dye image (through color development), but the silver halide that remains after the negative silver image has been developed and bleached. This is also why in E6 processing, the first developer is in fact not a color developer, but a (specifically formulated) B&W developer - we don't want to create a color dye image yet in the first developer as that would be a color negative image which we don't need (or want)! The color image is created in the subsequent color development step which acts on the remaining silver halides that were not involved in the first development.but i still don't grasp how would the slide (except kodachrome) would be colourizable after complete bw as kodak states.
The aspect you seem to have skipped earlier by the looks of it is the bleach step of the silver image. That one is essential in making a color image from a B&W-processed color film. However, the tech pub does not necessarily bear any relevance on your E-6 experiments. For your purposes, it makes more sense to look at detailed descriptions of E-6 processes, the various steps in the E-6 process, what purpose they serve and what kind of chemistry is generally used for them. There's been quite some discussion on DIY variants of E-6 in the past, in particular the first developer step, so you may want to do some searching on that. You'll find that a lot has been tried and there are some formulas out there that (kind of) work in a DIY setting.if you want to check the thing to see if i am missing something...
https://125px.com/docs/techpubs/kodak/ae31.pdf
You're welcome. Keep an eye out for some people more knowledgeable than me to come by and set the record straight on anything I may have gotten wrong.Thanks for your huge patience in writing such a wonderfull lesson, Koraks.
Depends on what you mean by 'reversal bath' - as you imply, reversal is not really a single bath. The E6 process is roughly as follows:the reversal bath in e-6 is a non-rehalogenating bleach (and fogging), right?
Yes; if your lab can totally skip step 1 (first developer), that could work.so the easy way to do that would be "c)" on my first post: bw dev, not fix, skip dev in e-6 lab straight to reversal/fogging if they can do that.
The developers, and particularly the color developer, and potentially the chemical fogging bath can/will go bad on you after a few weeks, so that may be a factor in planning your process. You may or may not get satisfactory results with partly home-brew chemistry, especially the three components I mentioned. Personally I'd use a ready-made bleach and fix as those are uneconomical to DIY in any case. The first developer is always a bit finicky due to the necessity of a developing agent that is very hard to come by.[/quote]about doing the whole e-6 thing at home: i am not afraid of the process. the hard part for me is getting a hold of the chemistry and putting use for the gallons i'll have before it decays (and throw quite a lot of money down the drain) . that is why i rather have only the first dev and leave the rest for the lab.
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