Results 1 to 10 of 203

Thread: Obsidian Aqua, catechol staining developer

Threaded View

  1. #11

    Join Date
    Sep 2003
    Location
    New Berlin, Wi
    Posts
    1,248

    Re: Obsidian Aqua, catechol staining developer

    Quote Originally Posted by Jay DeFehr View Post
    John,

    Yes, the stain is proportional, and the same brown-ish color as other catechol staining developers.

    Evan,

    In my tests, OA produces a speed increase of about 1/3-1/2 stop over box speed with Low Frequency Agitation, and rotary processing costs up to a full stop, or about 1/2-2/3 stop under box speed. Except for the speed loss, OA is excellent for rotary processing, producing no fog or general stain, and very even development with no streaking or mottling, but it really shines with Low Frequency Agitation, where it produces maximum acutance and compensating effects. But, if you can live with the speed loss, I think you'll be very happy with your results from rotary processing, too.
    I'll try to post an example of OA with rotary processing.

    Thanks, I rate 400 TMY at 320 when metering and Pyrocat MC is one of my developer choices, I always make at least two duplicate sheets. I'll make this tomorrow and compare this weekend..Thanks, Evan
    Last edited by evan clarke; 16-Feb-2012 at 12:38. Reason: Operator error

Similar Threads

  1. Glycin and staining developers
    By Jarin Blaschke in forum Darkroom: Film, Processing & Printing
    Replies: 15
    Last Post: 3-Aug-2012, 04:50
  2. pyro developer, but which?
    By sergiob in forum Darkroom: Film, Processing & Printing
    Replies: 206
    Last Post: 25-May-2012, 18:06
  3. Ideal Developer for Film to be Scanned
    By Jay DeFehr in forum Darkroom: Film, Processing & Printing
    Replies: 34
    Last Post: 12-Apr-2010, 05:09
  4. Which staining developer?
    By Leonard Metcalf in forum Darkroom: Film, Processing & Printing
    Replies: 21
    Last Post: 21-Oct-2007, 08:13
  5. Old Formulas : Film
    By Paul Fitzgerald in forum Darkroom: Film, Processing & Printing
    Replies: 6
    Last Post: 19-Mar-2005, 20:31

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •