Switch to English Language Passer en langue franšaise Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,220   Posts: 1,532,316   Online: 965
      
Results 1 to 10 of 10
  1. #1
    thefizz's Avatar
    Join Date
    Dec 2004
    Location
    Trim, Ireland.
    Shooter
    Medium Format
    Posts
    2,039
    Images
    37

    Dilution & Agitation

    Dilution: I mostly use Rodinal 1:25. If I try 1:50, what differences can I expect from my negs.

    Agitation: What will increased agitation do for my negs?


    Thanks,
    Peter

  2. #2
    titrisol's Avatar
    Join Date
    Aug 2004
    Location
    Rotterdam
    Shooter
    Multi Format
    Posts
    1,671
    Images
    8
    If you dilute Rodinal 1+50 or 1+100, times should be increased. our negatives will look smoother, drop contrast a bit and grain will be smaller (IMHO)

    The mlre you agitate the more contrast you create on the negative, the shorter the time you should develop.
    If you plan on diluting rodinal, you want to cut you agitation to once every other minute or so.
    Mama took my APX away.....

  3. #3

    Join Date
    Oct 2003
    Location
    ┼rhus, Denmark
    Shooter
    Medium Format
    Posts
    2,102
    Images
    16
    Quote Originally Posted by titrisol
    If you dilute Rodinal 1+50 or 1+100, times should be increased. our negatives will look smoother, drop contrast a bit and grain will be smaller (IMHO)

    The mlre you agitate the more contrast you create on the negative, the shorter the time you should develop.
    If you plan on diluting rodinal, you want to cut you agitation to once every other minute or so.
    I simply second that!

  4. #4

    Join Date
    Dec 2004
    Location
    Milwaukee, Wi
    Shooter
    35mm
    Posts
    3,242

    Go easy with the agitation

    The purpose of agitation is to bring new devloper into contact with the emulsion. Whatever amount of agitation is used should be gentle to prevent developer from surging thru the sproccket holes when using a film with sproket holes.

  5. #5
    titrisol's Avatar
    Join Date
    Aug 2004
    Location
    Rotterdam
    Shooter
    Multi Format
    Posts
    1,671
    Images
    8
    PS. I have settled for Rodinal 1+50 as standard dilution and 1+100 for EFKE 25.

    Quote Originally Posted by modafoto
    I simply second that!
    Mama took my APX away.....

  6. #6

    Join Date
    Oct 2003
    Location
    ┼rhus, Denmark
    Shooter
    Medium Format
    Posts
    2,102
    Images
    16
    Quote Originally Posted by titrisol
    PS. I have settled for Rodinal 1+50 as standard dilution and 1+100 for EFKE 25.
    1+50 is my mantra

  7. #7
    thefizz's Avatar
    Join Date
    Dec 2004
    Location
    Trim, Ireland.
    Shooter
    Medium Format
    Posts
    2,039
    Images
    37
    Thanks folks.

  8. #8

    Join Date
    Jan 2005
    Shooter
    Multi Format
    Posts
    284
    The way I understand it, though I could be corrected is in periods where no agitation is happening the developer in contact with very dense regions of the negative becomes exhausted much before the thin areas. Thus, if you leave a tank sitting the developer will work on the hilights and stop (for lack of a better word) developing the shadows very much, resulting in a lower contrast between shadow and hilight the less you agitate and more stark contrast the more you agitate because you are putting 'fresh' developer on those shadow areas.

    (experts, is this correct?)
    "Where is beauty? Where I must will with my whole Will; where I will love and perish, that an image may not remain merely an image."

  9. #9
    Donald Qualls's Avatar
    Join Date
    Jan 2005
    Location
    North Carolina, USA (transplanted from Seattle)
    Shooter
    Multi Format
    Posts
    1,845
    The other thing you do, by increasing contrast via agitation and compensating with shorter development, is lose shadow detail. The shadows get about the same amount of development from the same time in the soup, regardless of agitation, because the developer doesn't exhaust in shadow areas (thus bringing in fresh developer has little effect in those area). So, developing longer with less agitation to get the same overall contrast will increase shadow development (which increases the real film speed). Likewise, higher dilution (which also requires longer development to obtain the same contrast) will do the same, again because even the dilute developer doesn't exhaust in the shadows.

    I've wondered if the main reason people find they need to expose at 2/3 to 1 stop under the film's rated speed isn't because they agitate too much or use too fast a process. I use a highly dilute developer, reduced agitation (10-15 seconds every 3 minutes), and develop for 3-4 times the manufacturer's times for "normal" strength developer -- and with the manufacturer's rated speed, I never have problems with lack of shadow detail unless I simply didn't give enough exposure.

    Oh, and I get these effects with TMY -- in theory, they should be stronger with "traditional" grain films like Plus-X or Tri-X; that does seem the case with J&C Pro 100, with which I've gotten excellent shadow detail.
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  10. #10
    Will S's Avatar
    Join Date
    Nov 2004
    Location
    Madison, Wisconsin
    Shooter
    Multi Format
    Posts
    698
    Images
    34
    Quote Originally Posted by Donald Qualls
    I've wondered if the main reason people find they need to expose at 2/3 to 1 stop under the film's rated speed isn't because they agitate too much or use too fast a process. I use a highly dilute developer, reduced agitation (10-15 seconds every 3 minutes), and develop for 3-4 times the manufacturer's times for "normal" strength developer -- and with the manufacturer's rated speed, I never have problems with lack of shadow detail unless I simply didn't give enough exposure.

    Oh, and I get these effects with TMY -- in theory, they should be stronger with "traditional" grain films like Plus-X or Tri-X; that does seem the case with J&C Pro 100, with which I've gotten excellent shadow detail.
    Maybe. I think most developer times are too long, resulting in blocked highlights. Barry Thornton has an interesting article at:

    http://web.archive.org/web/200402020...uk/devtime.htm

    where he outlines how to test dev time.

    Thanks,

    Will
    "I am an anarchist." - HCB
    "I wanna be anarchist." - JR



 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  Ś   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin