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  1. #71
    Worker 11811's Avatar
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    More thinking...

    Why am I trying to use a helicopter to cross the street?
    Yes, my idea is workable but it's too complicated.

    I could just use the already existing G-3 tank. Few modifications would be needed.

    We only need to modify the reels inside the tank so that they allow the solutions to circulate around the film.
    As they are, the convolutions of film lay together as it rolls up. Not enough solution is in contact with the film.
    This is the main problem with the G-3 tanks.

    However, we've got something working for us: Short film. Only six feet.
    Can we make a reel that fits the existing tank which keeps the film apart? Possibly.

    The tank already has an exposure portal. We only need glass filters to color the light properly.

    1) Put film in tank, base side out.
    2) Remove rem-jet. Develop. Wash. No counting needed. Just crank the cranks.
    3) Place the filter. Open the portal. Crank to expose.
    4) Redevelop #1.
    5) In the dark, flip the reels over, putting the emulsion side toward the portal.
    6) Repeat steps 3 & 4.
    7) Chemically fog, redevelop and complete the rest of the process.

    It's a little more work, a little more thinking and not as automatic but I don't think this is beyond the ken of anybody here who already knows how to develop reversal film processes. It just takes more steps.

    It uses existing equipment with only a few modifications.

    We only have to work out the modifications to the reels.

    Stephen already knows the chemistry.

    I think this could work.

    Addendum:

    What if we wound a piece of mesh or similar material up on the reels as the film goes on?
    No modification needed. The mesh would hold the convolutions of film apart enough to allow solutions to circulate.

    What kind of mesh or "spacer" material could we use?
    Last edited by Worker 11811; 03-31-2012 at 02:37 PM. Click to view previous post history. Reason: Addendum
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

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

  2. #72
    Photo Engineer's Avatar
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    Well Randy, we use 2L graduate cylinders for 35mm film. There was a weight and the film was looped. It was removed from the tank and hung in a rack for manual re-exposure. It is difficult to overexpose the red IIRC. Nothing else is red sensitive, Then the film is hung up again and the process is continued. Etc.

    Your "mesh" system was once used by the EK 35mm tank. They used crinkled "aprons" to hold the film in a spiral and yet hold the emulsion and base apart on each part of the spiral. I have one here somewhere. Nice system.

    But by your analysis, you did see elements of the complexity that I alluded to. Your second method is more sound and less costly.

    PE

  3. #73
    Worker 11811's Avatar
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    How about a series of plastic, ladder-like links which hook together to form a chain.

    This plastic chain would be wound up on the reels with the film to act as a spacer to let the chemistry circulate around the film.

    After that, we need to be sure we have the correct color filters of quality to do the job, a standardized light source and a repeatable formula for chemistry and it *MIGHT* be possible to do this in your basement.

    We're not out of the woods yet, though. Still have things to work out... Still thinking...

    P.S. -- The Morse G-3 developing tank: http://www.marriottcameras.co.uk/ins...h_pictures.htm
    Attached Thumbnails Attached Thumbnails Chain 1.png   Chain 2.png  
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

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

  4. #74

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    Wouldn't the ladder "rungs" press against the emulsion side too, to detrimental effect? The plastic aprons mentioned earlier attempt to avoid this by only really touching the film at the edges, which not only spaces the film out from its neighbor in the coil, but also from the apron itself.

    Image stolen from ebay:

    Click image for larger version. 

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    Duncan

  5. #75
    Worker 11811's Avatar
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    The rungs of the ladder are smaller diameter than the rails. That part wouldn't touch the film at all. Only the rail part touches the film.

    However, I like your plastic apron better.
    It can't come apart like mine can. It's also thinner can can fit on the reel better and bend around corners more easily.
    Best of all, yours is an already existing product. Mine would have to be manufactured.

    Now, last problem to solve...
    How do we flip the film over?

    Without the apron, we would simply flip the reel of film over but, because of the apron, we can't do that.

    Can we "S-Wind" the film, somehow?

    I'm usually good at this kind of topology but I need to see the real thing, first, in order to figure it out.
    Randy S.

    In girum imus nocte et consumimur igni.

    -----

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

  6. #76
    Stephen Frizza's Avatar
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    Quote Originally Posted by ME Super View Post
    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.
    this is correct.
    "Its my profession to hijack time" ~ Stephen Frizza.

  7. #77
    Stephen Frizza's Avatar
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    Quote Originally Posted by Worker 11811 View Post
    More thinking...

    Why am I trying to use a helicopter to cross the street?
    Yes, my idea is workable but it's too complicated.
    I don't know but I do believe in keeping everything simple. I did not use light tight small tanks in my processing. My set up consisted of small tanks which I dip and dunk the film into. Each tank lain out in the processing sequence in a darkroom with the processing bay on one side of the room and my custom set up printing station for re exposure on the other.

    A few months ago I showed one of my autochrome style tests.... see link here

    http://www.apug.org/forums/forum42/7...chrome-10.html

    I came up with simple elegant working solutions to some of the problems in that thread, the proof was in the pudding. I mean no offense to anyone in that or this thread but if you read the following 25 pages of testing and theory and development in the link I didn't see anything close to my example or anything that could super seed it. I feel this thread may very well do the same. sorry to be so demotivate.
    "Its my profession to hijack time" ~ Stephen Frizza.

  8. #78
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    On the contrary Steve, you tell it like it is. In fact, if there was an award for APUG member of the year for outstanding achievement, I would recommend you! Good work on both counts. I would love to have one of those screens. Are you going to sell them?

    PE

  9. #79
    Toffle's Avatar
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    Quote Originally Posted by Photo Engineer View Post
    On the contrary Steve, you tell it like it is. In fact, if there was an award for APUG member of the year for outstanding achievement, I would recommend you! Good work on both counts.

    PE
    +1
    Tom, on Point Pelee, Canada

    Ansel Adams had the Zone System... I'm working on the points system. First I points it here, and then I points it there...

    http://tom-overton-images.weebly.com


  10. #80

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    Does this mean I can finally expose all of the Kodachrome in my freezer?

    For the record, the only film I have left (after going to a big event this weekend) is 5 rolls of some E-4 Ektachrome films and 10-15 rolls of Kodachrome.

    Nice work, Mr Frizza.

    -R
    Last edited by ricardo12458; 04-01-2012 at 04:48 PM. Click to view previous post history.



 

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