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  1. #11
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    For those interested in a monochrome developer for Kodachrome to give a negative dye image, here is the basic formula and the basic problem involved:

    1. Use a normal C41 developer, but add a Kodachrome type coupler such as a cyan, magenta or yellow. (I can post these later if you wish, as I don't keep them in my head).

    2. Develop in this C41 developer to get a monochrome image of whatever color you have designed for in 1 above.

    3. Bleach, fix, wash and stabilze as normal.

    4. The process must be at 68 - 75 deg F as older films and B&W films (yes this will work for B&W as well as Kodachrome) cannot stand higher temps. You will have to do some tests beforehand to determine development time, but my tests indicate that it will be on the order of 15' - 30' at 70 deg.

    Problems:

    1. The final image will only be as stable as the dye formed. Since we will never be able to readily get the real Kodachrome couplers, the ones we would use would be bottom of the line stuff. Not very good for much of anything but fundamental imaging.

    2. The chemicals (couplers) are going to be expensive.

    PE

  2. #12

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    Hi PE,

    Thank you for the info. I would appreciate your info concerning Kodachrome-type couplers when you have it conveniently at hand. Even if it is too expensive/impractical/etc. I would like to consider trying it.

    Cheers,
    Clarence

  3. #13
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    According to Leadly and Stegmeyer, the use of 2, 4 dichloro-1-napthol at 1 g/l added in an acetone solution (I would use either methyl or isopropyl alcohol myself) will give a cyan image.

    This is better than using the actual Kodachrome coupler and developer which is complex and expensive, and it is a good starting point.

    PE

  4. #14
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    I like that idea, PE; where can you get said coupler??

    Also, there are chromogenic toning kits (Rockland has one for $50 - ish), so those would probably be another option.

  5. #15
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    IDK where to get the coupler. The toning kits are based on existing silver images IIRC.

    PE

  6. #16
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    Quote Originally Posted by CRhymer
    I use D-19 for all my b&w reversal processing - used the Kodak t-max reversal some years ago, but it was pricey. D-19 is actually relatively cheap in Canada - $5.19 CDN (powder to make 128oz.) plus flat rate shipping from Henry's - a big issue with me so I buy 20 at a time. I don’t think they ship chemicals to the US - although it is no big deal to make your own.
    I have everything I need to make D-19 unless it's got something odd in it. Lemme look -- yep, metol, hydroguinone, sodium carbonate, sodium sulfite, and potassium bromide. Twenty minutes, starting from checking that the wife won't need the bathroom, er, darkroom. I've even got sodium hydroxide on hand to make the replenisher, if desired.

    Many reversal procedures call for a high contrast first developer. I know very little about K-12 as b&w (except for a few trials) but the K-14 I developed as a negative in Rodinal looked like Tech Pan. I prefer re-exposure to a fogging redeveloper. For movie film I usually second develop to completion, so there is not really a lot of tweaking after the first steps. I don't know if you have done reversal before, but it is a lot of fun and potentially addictive.
    This is the way I've always read it should be done -- all steps after first dev carried to completion; any contrast controls are done in the first dev. I've also read on several occasions that some thiosulfate (got a few pounds) added to the first dev helps clear the highlights by removing the extra-fine halide grains that never develop and are usually fixed away, even in the hottest highlights.

    I usually use permanganate bleach, partly because I had it at hand first. I use potassium dichromate for gum printing (more recent habit). It is probably preferable for reversal than permanganate although somewhat more toxic.
    The biggest issue with dichromate (which I also bought mainly for gum and similar processes, but then neglected to buy any gum arabic -- possible substitute in hand, just need to test) is that, many places, it's literally a crime to put it down the drain, because of environmental concerns with the hexavalent chromium (and never mind that it doesn't and can't stay hexavalent long in an environment like sewage, rich in weak reducing agents that will tend to quickly take up the oxidation potential of the chromium). And of course there are "national security" issues with both because they're oxidizers -- but I have dichromate and I don't have permanganate, so dichromate bleach it'll be (though I might yet get a can of tree root killer from the hardware store and try copper sulfate as a bleach -- I've heard it reviled, but don't think I've heard of anyone using the formulae I've seen that effectively mimic permanganate or dichromate reversal bleaches. And it's cheap, typically around US$7 per pound.

    I am still musing about the monochrome dye negative developer - could be interesting.
    Ron has corrected my confusion on that -- the dye toner kits are fogging redevelopers, not latent image developers like C-41 color dev. They'd be usable to obtain a dye positive from Kodachrome, however; suitable first dev, color toner dev, rehalogenating bleach (C-41 bleach would be least likely to damage the dye image) and fixer. Simpler process (slightly) than B&W reversal, but still issues with permanence of the dyes; they're intended for prints for special purposes, not for archival longevity. Probably not worth the effort.

    I'll probably try B&W reversal on Tri-X (mostly because I have a lot of it still around) in the next week or two, now that I have a cube of battery acid on hand. Four bucks for a quart of 33.5% sulfuric, I figure that's a multi-year supply... And while there's no telling what impurities are in there, it's been reported by many others to work fine in reversal bleaches.
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  7. #17

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    Hi Donald,

    I'm sure you will do fine with dichromate. Copper sulphate may work, but we know that dichromate will work well. In fact, now that I have some mixed up for testing, I will probably switch for my movie film reversal (I use a saturated solution for stock in gum printing). Yes, other gums will work, or you could do egg tempera. I have used a number of gum arabic sources, but have recently changed to Daniel Smith's "pit run" variety - works well and has preservative - thanks to the advice of Judy Seigel (alt-photo-process list and World Journal of Post Factory Photography - kind of off the wall, but useful and entertaining). I had to wait until past the threat of frost before getting it shipped to the North. Permanganate is stable until it is mixed with acid, then must be used promptly and discarded. Dichromate can be premixed and reused. I agree about disposal, but you can always just add some sulphite to it before you dump it. The biggest risk with dichromate is weighing and mixing the powder - a face mask, old newspaper under the works, and rubber or nitrile gloves are a good idea. Discard the newspaper and mask after mixing. Of course, at least the dichromate can be easily seen due to the bright colour - true for permanganate as well.

    The T-max reversal kits had some info about adjusting the second developer time, but I have never bothered. I don't usually use a halide solvent, but have sometimes regretted it. Thiocyanate probably works a bit better and is not a problem at the low levels used, but hypo (which you have) works fine as well. As I recall, it is best to add it just before you start development. If you re-expose there is the possibility of printing out by overdoing it, which I think I actually did once, but there is a lot of latitude, so it is not likely to be too big a concern.

    One thing that I have never addressed adequately is the adjustment in exposure to negative films for reversal processing. Kodak has recommendations for Tech. Pan and T-max 100 for their reversal kit, but I am not sure what speed to shoot Tri-x at to achieve sufficient gamma – it may depend on which Tri-x you have. The dr5 site has some info at: http://www.dr5.com/filmprintout.html for their process.

    I have used a number of 16mm movie negative emulsions for reversal, and found that they usually worked better when shot at half their rated speed (increased exposure). Some were out dated, but not ancient.

    There are also many suggested development times for the first developer. I have found that 8 minutes @ 20 degrees C. for D-19 (with pre-soak) is a good starting point for movie film.

    I would be interested in your experience with Tri-x.

    Cheers,
    Clarence

  8. #18
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    posted by PE:
    The toning kits are based on existing silver images IIRC.

    The rockland one is actually couplers and a p-phenylene diamine based developer.

  9. #19
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    Quote Originally Posted by htmlguru4242
    posted by PE:



    The rockland one is actually couplers and a p-phenylene diamine based developer.
    You are correct.

    I was referring to true toning in color which relies on pre-formed silver images. Sorry for the error in my post.

    You have to start with an undeveloped film for the rockland toners to work, and they would work fine with Kodachrome. AAMOF, one could develop Kodachrome given CMY toners. Although I would call them color developers.

    You can also bleach an already formed silver image back to a silver halide with a rehal bleach and then 'tone' in the rockland 'developers'.

    PE

  10. #20

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    To get a printable negative image just use a staining developer based in pyro or catechol and after development bleach out all the silver. No need to buy a coupler and any other exotic chemicals.

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