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  1. #21
    dr5chrome's Avatar
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    not what i implied at all PE. you may imply what ever you wish. just trying to strike up a conversation. lets forget I brought it up.

    best.

    dw


    Quote Originally Posted by Photo Engineer View Post
    Well, then, it has become obvious to you that I know nothing about the "R" processor only the color "R" process itself and got them confuse having no information on hte former.

    PE

  2. #22
    Photo Engineer's Avatar
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    Quote Originally Posted by dr5chrome View Post
    not what i implied at all PE. you may imply what ever you wish. just trying to strike up a conversation. lets forget I brought it up.

    best.

    dw

    Sorry, no implication implied or expressed. I simply know nothing about the "R" processor and that is all I can say..

    PE

  3. #23

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    To report back regarding the original query: With further tests I was able to get the reversal process to work just fine. It turns out that my exposures had been underexposed by a stop or so.

    At first I got what looked like a proper negative exposure (processed normally before bleaching) using a meter reading and adding 3 stops. That resulted in an almost completely dark product. Here's what finally worked for me using Agfa RC paper: using a meter I got the exposure for ASA 8 (the lowest asa my meter registers), then added about 4.5 stops. My final working exposure was 1 minute at F11 using tungsten lights.

    The final product was a bit contrasty using either developer, but I have yet to try it with a low contrast subject. And of course, the paper is not panchromatic. My original intention was to use this process in order to use photo paper in my 8x10 camera to save money. Now I am thinking to use it with 16x20 paper in a 16x20 pinhole camera!

    Thanks to all who answered my initial query, and I hope this writeup will help others attempting the process.

    For the sake of the archives, I found that I did not need to add the solvent (sodium thiosufate) to the first developer as some had suggested. I tried D-19 (a high contrast developer) with the added solvent and got pretty much the same results as by using my regular paper developer with nothing added. I used LPD for both my first and second developers, 1:1 with water, and I assume you could use Dektol or other developers with similar results.

    You can get details of the B&W paper reversal at:
    http://members.iinet.net.au/~forbes/reversal.html

    Another page that is really helpful is Donald Quall's page:
    http://silent1.home.netcom.com/Photo...d%20Times.html
    along with many other formulas and tips.
    Keith Ostertag
    keitho at strucktower dot com

  4. #24
    Nicholas Lindan's Avatar
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    Quote Originally Posted by keithostertag View Post
    It turns out that my exposures had been underexposed by a stop or so. ... I found that I did not need to add the solvent (sodium thiosufate) to the first developer as some had suggested.
    That mimics my experience - that you have to overexpose the bejesus out of the material. I imagine if an area is to be white in the final print then it is necessary to first turn every particle of silver halide black so it can be bleached away. My work with making enlarged negatives from Arista lith film required enough exposure to turn the film jet black - detail could only be seen by shining a light through the film. When in the bleach the darkest areas of the negative went quite transparent and remained that way when the film went into the second developer.

    I found that thiosulfate in the developer just 'fixed' away the image before the developer could act.
    DARKROOM AUTOMATION
    f-Stop Timers - Enlarging Meters
    http://www.darkroomautomation.com/da-main.htm

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