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  1. #11
    Derek Lofgreen's Avatar
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    David,
    You rock! Thanks for the links.

    D.
    My Photography Site www.lofgreenimages.com and My Blog

  2. #12

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    Thanks David That's a big help.

    pentaxuser

  3. #13
    hka
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    Does it only work with Dektol?? or is any other standard b&w developer usable?
    harry

    Release, the best you can do...

  4. #14
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    D76 will not work in my experience. Probably no solvent developer will. The paper emulsions are too soluable and you lose a huge chunk of speed.

    PE

  5. #15

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    Quote Originally Posted by pentaxuser View Post
    Like the others I am fascinated by this. I have several dozen transparencies but gave up shooting more because of the expense of the Ilfochrome process for making prints using this processand
    I wouldn't count on RA-4 reversal as a substitute for Ilfochrome (or discontinued reversal papers/processes). Results tend to be high in contrast and the color balance tends to be a little weird. Some paper/developer combinations produce mottling. If you've got the right subject, the results can be good (either because the problems are minimized or because the odd characteristics work with the subject), but as a general-purpose way to get prints from slides, I don't think RA-4 reversal is a good way to go.

    OTOH, perhaps there's some "magic combination" of paper and developers that will make it work well. If so, I've neither found it nor heard about it.

    By all means, experiment. I've got a print hung on my wall that was made with this process. I've got more prints from slides hung on my walls made by scanning and digital printing, though.

  6. #16
    amellice's Avatar
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    What is the purpose of re-exposing? I'm not clear on this step. Is it just open the room light for 15 seconds on the front of the paper (emulsion side) and the back of the paper? What is then the back has to do with it? Can someone shed some light on the re-exposure step
    Akram
    https://500px.com/amellice

    Bracketing is the refuge of the unknowing, a trial-and-error procedure that is wasteful of film and weakens the sense of disciplined procedure. Ansel Adams

  7. #17
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    Quote Originally Posted by amellice View Post
    What is the purpose of re-exposing? I'm not clear on this step. Is it just open the room light for 15 seconds on the front of the paper (emulsion side) and the back of the paper? What is then the back has to do with it? Can someone shed some light on the re-exposure step
    As in any reversal chromogenic process (E6 comes to mind), a light re-exposure or chemical fogging step is needed to make the positive silver halide image developable.

    PE

  8. #18
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    Quote Originally Posted by Photo Engineer View Post
    As in any reversal chromogenic process (E6 comes to mind), a light re-exposure or chemical fogging step is needed to make the positive silver halide image developable.

    PE
    but what about exposing the back of the print? what difference does it make to expose the emulsion side for 30 seconds or exposing the emulsion for 15 and the back for 15?
    Akram
    https://500px.com/amellice

    Bracketing is the refuge of the unknowing, a trial-and-error procedure that is wasteful of film and weakens the sense of disciplined procedure. Ansel Adams

  9. #19

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    This has raised my interest again and also raised a number of questions which may be obvious to others but not to me.

    1. We know that Dektol works but would Ilford Multigrade B&W developer also work?

    2. The times given by PE for the RA4 processing are, I assume, for room temp processing. Would 35C in a Jobo with times altered for 35C work also?

    3. We know the time used by PE when projecting the transparency onto the RA4 paper but is there any way to estimate what the right time is or is it simply a question of lots of test strips, using a F4 aperture?

    4. We also know the M and Y balance used but is this close to what all transparencies will need and if so what was the enlarger system used i.e. Durst, Kodak filter values? If the balance varies a lot between each transparency, how does one begin to work out what the balance might be?

    5. Once the RA4 paper has been developed in Dektol or other suitable B&W developer, what appears on the paper- a negative in B&W? If at this stage the RA4 has been used for test strip columns can you work out which is the right exposure?

    6. I assume that the RA4 paper needs to be exposed under the enlarger in either total darkness or colour safelight. If so, at what point can the lights go on and stay on?

    Some of these questions may seem naive but any help will be appreciated on this.

    Maybe the answers can be added to the very good pdf that a APUGer has compiled on PE's process

    Thanks

    pentaxuser

  10. #20
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    Quote Originally Posted by amellice View Post
    but what about exposing the back of the print? what difference does it make to expose the emulsion side for 30 seconds or exposing the emulsion for 15 and the back for 15?
    The negative image can shield any image behind it, so you have to expose front and back. This is also true with E6 light reversal.

    PE

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