Rodinal confusion

Discussion in 'The Darkroom' started by Grandpa Ron, Aug 7, 2019.

  1. Grandpa Ron

    Grandpa Ron No longer a newbie, moving up!

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    In a previous post I was looking for a mix as needed developer and Adox Rodinal was suggested.

    I have been doing a bit of tail chasing trying to determine the proper Rodinal mixture for 4x5 film.
    • My tank holds 55 oz. or 1627 ml and will process 1 to 12 4x5 sheets. I typically process 4 to 6 sheet in a session.
    • I believe I read that for an 8x4 sheet, a minimum of 5ml of Rodinal is recommended. This would be 4 sheets of my 4x5 film. However, I do not know if this is for tray or tank development. I am looking for tank information.
    • If I were to do 12 sheets of 4x5 that would require 15 ml developer but only produce 750 ml of a 50:1 mixture which is less than 1/2 what I need in my tank.
    • So, to maintain a 50:1 ratio I would need 32.5 ml of developer. Or, 65 ml at 25:1 in my 1627 ml tank.
    If I am correct, I need to maintain the 50:1 or 25:1 developer mixture, regardless of any minimum developer data. Is this correct?


     
  2. Tim Tucker 2

    Tim Tucker 2 No longer a newbie, moving up!

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    Yes you need to maintain the dilution, i.e. mix enough to fill the tank at say 50:1. It is the surface area/dilution that's important and this dictates the minimum quantity of developer otherwise it will exhaust before the sheet is developed.
     
  3. Grandpa Ron

    Grandpa Ron No longer a newbie, moving up!

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    Thanks Tim,

    This 4x5 format has been a steep learning curve, but it is so intriguing you just cannot stop.
     
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  4. ac12

    ac12 Been spending a lot of time on here!

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    It has been way too many years, but as I recall, agitation affects the film contrast with Rodinal.
    I "think" Rodinal was meant to be used with minimal agitation, to bring out the shadows.
    Agitate too much and it becomes a high contrast developer.

    Hopefully, someone with more recent Rodinal experience will speak up.
     

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