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  1. #61
    Stephen Frizza's Avatar
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    Quote Originally Posted by wblynch View Post
    If it were me I would create a 'stretcher' or rack where the film strip gets mounted all flat out. Then a set of long troughs, or tall cylindrical tanks that the stretcher would be immersed in. You could easily control the reexposure by side and light color by placing the rack on a light bar.

    Although I'm sure you would have to process in darkness, it could be an assembly line type of affair. Drop in tank1 for time, pull the rack out and on to light bar 1, then on down the line.
    For my printing stages I used one of those curved black duping easels it held the film nicely, protected the side i wanted protected during the re exposure etc...
    One thing that is paramount in the process is making sure when you expose a layer you expose it completely without effecting the other layers. In exposing a layer completely the dye development baths will dye the film correctly however if you don't entirely expose the entire red or blue layer to completion when it comes time to doing chemical reversal of the green layer the left over silver halides in the other layers develop in the magenta dye bath and cause colour contamination (sorry Ron if you think my terminology is off) but im sure u know what I'm referring to at this step.
    "Its my profession to hijack time" ~ Stephen Frizza.

  2. #62
    Stephen Frizza's Avatar
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    Quote Originally Posted by Photo Engineer View Post
    I have just about everything to do this, but want to confirm sources and chemicals with Steve.

    PE
    Ron I will send you a private message about source of chemistry for the process.
    "Its my profession to hijack time" ~ Stephen Frizza.

  3. #63
    Stephen Frizza's Avatar
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    For those whom are not aware of what is involved in processing Kodachrome here is a very lay mans step by step of the process.....

    After mixing up your chemical solutions (tedious in its own right) and preparing wet and dry work space this is what is required to process this film....

    The basic steps of the process are as follows....

    Step 1 = Alkaline bath for removal of rem jet layer
    Step 2 = Wash
    Step 3= first developer
    Step 4= wash
    step 5= Exposure of unexposed silver halide in the red layer of film (though base non emulsion side)
    step 6 = cyan developer
    step 7 = wash
    step 8= blue layer re exposure (via emulsion side)
    step 9= yellow developer
    step 10= wash
    step 11= chemical reversal of green layer
    step 12= wash
    step 13= magenta developer
    step 14= wash
    step 15= Pre bleach bath
    step 16= bleach
    step= 17 Fixer bath
    step 18 = wash
    step 19 =stabilizer
    step 20 dry.......
    "Its my profession to hijack time" ~ Stephen Frizza.

  4. #64
    Thomas Bertilsson's Avatar
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    Stephen,

    Quite the accomplishment. Very well done, and thank you for sharing your findings!

    - Thomas
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  5. #65
    Worker 11811's Avatar
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    I'm thinking of some ideas that could make this process doable in a home lab. It's strictly theoretical. "Vaporware," if you will:

    I have a tabletop reversal tank for movie film. It's called "Morse G3."
    It's a large daylight tank with two reels inside used to crank film back and forth, through the developing solutions. There's a window on the side used to let light in for the re-exposure steps. You open the window, shine a light through the portal and crank the film, slowly, past the light stream.

    The problem with this tank setup is that it's very hard to get even, predictable development owing to the fact that, most of the time, the film is wound up on reels. The film can't get evenly wet by the chemicals.

    However, if we're developing 35mm rolls of still camera film, we're only talking about lengths of film 1 or 2 meters long. It might be possible to create a labyrinth system of rollers inside the tank that keeps the film submerged in the chemistry at all times. If we splice a piece of Mylar film onto the tail of the roll of film to be developed, we can create a mobius loop. Each time you cycle the film around the "track" it flips over. First the emulsion side of the film faces the window then, on the second lap, the base side of the film faces the window. Just turn the crank and the film is re-exposed in the proper order.

    Placing a glass filter over the window ensures the correct color of light exposes the film. On the first lap, the red filter is placed over the window. On the second lap, the blue filter is used. On the third lap, no filter is used.

    Let's imagine how this might all come together:

    Place the head end of the film into feed roller of the tank. There's already a length of Mylar threaded through the labyrinth system. All you have to do is splice the head of the film to the tail of the Mylar and turn the crank until the film is fed in. At the end, splice the end of the film to the end of the Mylar loop, making sure the film is twisted to create the mobius loop. Close the tank and prepare the chemistry.

    Chemistry could be distributed in paper juice boxes. It's pre-measured and ready to use but for mixing. (Which I'll deal with in a moment.)

    Temper the juice boxes by submerging in hot water until they are the right temperature. Because paper juice boxes have a little hole in them, used to poke the straw through, we could use that hole to poke in a thermometer. Submerge in hot water and gently shake every few minutes until they are at the right temperature.
    When the temperature is right, tear open the spout and pour into a container to mix the "A" and "B" solutions if necessary. No measuring. It's already pre-measured. Just pour and stir.

    Put the solutions into the tank and turn the crank to agitate. Open a valve at the bottom and drain out the solution when it's time.
    Pour in the next solution or rinse water, crank, time and drain. Repeat with each solution, in turn, as necessary.

    When it's time to re-expose the film, place the correct glass filter in the holder and open the port hole. Crank the film past the window at the right speed until all the film has passed the window. Close the portal and continue with the redeveloping solutions.

    At this point, the mobius loop will have caused the film to turn over so that the other side faces the window. If all is done right, you should be able to crank the film past the window using the other filter to expose the back side. When done, close the window again and redevelop the second time.

    For the third redeveloping step, don't use any filter. Just crank the film past the window with no color and go for the third redevelopment.

    Close the window, rinse, fix, condition or what-have-you. When finished, open the tank, take out the film and dry.

    A tank for this purpose would probably have to be, maybe, two feet long, a foot wide and at least six inches tall. It would be a fairly large tabletop unit. That gives some room to add some extra gewgaws.

    An electronic, digital timer could be built into the top of the unit which is preprogrammed with the times needed for each step. Press the right button to set the preprogrammed time and hit the "start" key. The timer counts down, beeps to remind you when to agitate and beeps continuously when the time is over.

    The color filters could be a red, blue and clear glass disk that rotates behind the window. Simply turn the knob to place the right color over the portal.

    The Mylar leader could be colored so that you can see it through the window. It could have numbers of symbols printed on it.
    At the start of the first round, a number "1" will show through the window. At the end, of the first lap an "1-X" could appear.
    For the second round, a "2" and a "2-X" could appear.

    A notch could be cut in the edge of the Mylar leader that allows a cam and follower mechanism to warn the user when he has turned the film for a complete lap through the system. The cam could ring a bell, set off an electronic beeper or advance a mechanical counter that lets the user know how far to turn the crank and advance the film.

    Theoretically, the whole thing could be motorized or, if an Arduino microprocessor is used, the whole thing could be automated.
    If you really wanted to guild the lily, the filling and draining of chemistry could be automated, too.

    However, at first, I would shy away from too much automation because it would make the whole thing too expensive.

    The main problem I see with this setup is cost. It would be expensive to develop and costly to sell.
    I don't know if there is enough undeveloped Kodachrome still left in the world to make this a worthwhile project.
    Maybe, if I had thought of this ten years ago, the situation might be different.

    However... "Chicken and the egg"...
    If somebody could produce these kits at a price people could afford, maybe they'll create enough demand for product that somebody would be able to produce it.

    I know, it's wishing in one hand and sh*tting in the other.

    P.S. - If anybody ever develops this product and makes it to market, I don't want money. All I want is free product for life.
    Last edited by Worker 11811; 03-31-2012 at 01:25 PM. Click to view previous post history.
    Randy S.

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  6. #66
    Photo Engineer's Avatar
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    Randy;

    Admirable but still with unsolved questions!

    Where do you get the chemicals and what are they? How are they mixed? What are the formulas for the solutions?

    There are 4 that I see.

    As for your process, there is a machine like that used for processing Aerial film. It is motor driven and the solutions are poured into the tank directly. We got good uniformity. I see it as workable. However, with a Mobius loop, how can you tell absolutely which side is facing the window after multiple rewinds of the film?

    PE

  7. #67
    Worker 11811's Avatar
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    Packaging, I've got worked out. Actual sourcing of chemistry, somebody else is going to have to work that out.
    Package it in paper juice boxes. Temper the sealed boxes in hot water. Tear open, mix and pour at the right times. It's all premeasured.

    Mobius loop: Put a notch in the edge of the Mylar leader. A cam and follower rides on the edge. When it hits the notch, it trips a mechanism which rings a bell, advances a counter or sets off an automated process on the microprocessor. (If a microprocessor is used.)

    If you can't use a cam and follower, strips of metal foil tape could be stuck on the film with adhesive. They move past a detector, the same way that is done on cinema projectors. (It's basically a miniturized metal detector.) The detector lights a light, rings an alarm or advances a counter.

    I prefer a cam and follower riding over a notch. That provides a positive stop at the right point in the process which lets you know the film is in position.

    BTW: I didn't pay attention. You don't have to re-expose a third time for the third reversal, do you?
    That makes it simpler. Only two laps around the track are needed instead of three. Only a red/blue filter is needed instead of white.
    I should have paid closer attention before going off on a tear.
    Randy S.

    In girum imus nocte et consumimur igni.

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    http://www.flickr.com/photos/randystankey/

  8. #68
    Photo Engineer's Avatar
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    In the processor that I used to use, the film was in constant motion back and forth for agitation and uniformity. It was motor driven by a light tight lid/motor combination that fit on top and allowed room light processing. I have forgotten how we changed the chemicals for some reason. Thats odd. I just went to my memory for that and there was a blank spot. Oh well, there was some type of chemical dump method...

    In any event, in an 8 minute first developer, I think that a large roll of Aerial Ektachrome made dozens of passes. By your scheme, this would result in many many reversals of the front-back relationship.

    There are 2 light reversal steps, but you can use white light or a fogging agent for the magenta layer making 3 light reversals. That is optional.

    PE

  9. #69

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    Right. The third reversal is a chemical reversal which renders all the remaining silver halide developable. I believe it's necessary to do it as a chemical reversal because silver in the red and blue layers could be blocking the green layer at this point. IDK though this is just speculation.
    ME Super

    Shoot more film.
    There are eight ways to put a slide into a projector tray. Seven of them are wrong.

  10. #70
    Worker 11811's Avatar
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    In a Mobius loop, the film turns over each lap through the system. First, the base side faces out then the emulsion faces out. (Or vice-versa.) Each lap changes the side facing in or out.

    Also, the top and bottom edges change places, too. What was, once, on top now becomes the bottom. Each lap changes the side facing up or down.

    Use a heavy piece of mylar leader. Double weight or whatever.

    Cut a notch in one edge of the mylar leader. Place a small roller that rides on the top edge of the film. Connect that to a cam and follower. Place a second roller, cam and follower on the bottom. Connect both cams/followers to an escapement. The escapement moves a gear which, in turn, moves a signal flag back and forth.

    Lap 1: The film goes around. The roller, cam and follower on the top falls into the notch as it passes. The mechanism moves and a little flag appears in a window indicating that the base is facing the exposure portal.

    Lap 2: The film goes around again. The roller, cam and follower on the bottom falls into the notch as it passes. The mechanism moves and a little flag appears in a window indicating that the emulstion is facing the exposure portal.

    On each successive lap, the notch goes from top to bottom, the rollers fall into the notch as it passes, moving the cams and follwers, advancing the escapement and changing the flag in the window from "base" to "emulsion" or vice-versa on every successive pass.

    As long as there is an even number of passes of the film through the system, the film will be in the same orientation it started in:

    • Develop for 8 minutes = 8 or 16 passes. (8 minutes from your example.)
    {Even number of passes leaves film is in the same orientation.}

    • Rinse for 1 minute = 2 passes.
    {Even number of passes leaves film is in the same orientation.}

    • Insert red filter. Open portal. Crank one pass. Close portal.
    {Odd number of passes. Film has reversed.}

    • Redevelop for X minutes = X or 2*X passes.
    {Even number of passes leaves film is in the same orientation but it has already been reversed from the preceding steps.}

    • Insert blue filter. Open portal. Crank one pass. Close portal.
    Redevelop for Y minutes = Y or 2*Y passes.

    Keeping track of the number of passes only requires the user to watch the flag in the little window.
    He needs to watch for "Emulsion" or "Base" to appear at the right times. (Could be "1" or "2". Could be "RED" or "BLUE.")

    At this point, if you're using chemical fogging, no more light passes are needed.
    You do not need to keep track of the number of passes. Just crank. The flag mechanism could still be used to count the number or laps around the track, if necessary. You just don't need to remember emulsion/base or odd/even anymore.

    What is the agitation scheme?
    How fast does it need to move?
    What length of time or how many laps does it need to make during one step of development?

    As long as you count the laps, keeping track of "odd" or "even" you sould be all right. The rest is just timing.
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

    http://www.flickr.com/photos/randystankey/



 

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