Results 1 to 6 of 6

Thread: agitation -- tank vs drum

  1. #1

    Join Date
    Jun 2006
    Location
    Westfield, New Jersey
    Posts
    417

    agitation -- tank vs drum

    Could someone venture a guess at a factor that can be applied if one is used to tank development (which allows inversion agitation plus stand time) vs. drum agitation (which doesn't allow any stand time)?

    For example, If I'm doing 4x5 FOMA 100 in d76 1:1 at 8 min. in an HP combi-plan, what would be a starting-off factor for the same film in 8x10 using a unicolor drum?

    I know, test--test--test, but I'm looking for at least a decent first shot time. I've heard a rough factor of 15-20% between either method.

    Thanks,

    George

  2. #2

    Join Date
    Sep 2003
    Location
    South Carolina
    Posts
    5,506

    Re: agitation -- tank vs drum

    Quote Originally Posted by gbogatko View Post
    Could someone venture a guess at a factor that can be applied if one is used to tank development (which allows inversion agitation plus stand time) vs. drum agitation (which doesn't allow any stand time)?

    For example, If I'm doing 4x5 FOMA 100 in d76 1:1 at 8 min. in an HP combi-plan, what would be a starting-off factor for the same film in 8x10 using a unicolor drum?

    I know, test--test--test, but I'm looking for at least a decent first shot time. I've heard a rough factor of 15-20% between either method.

    Thanks,

    George
    George,

    I would suggest reducing development time by about 15% with the drum, if using continuous agitation on a motor base.

    Sandy King

  3. #3

    Join Date
    Aug 2007
    Location
    MA/PA
    Posts
    184

    Re: agitation -- tank vs drum

    One thing that might be a factor is the speed at which the drum rotates. I found that with TMY I had to cut my dev time by 40% from the massive dev chart times. I think my base may rotate faster than most (it's about 30 RPM), beseler non reversing.

  4. #4

    Join Date
    Mar 2006
    Location
    Coast of Oregon
    Posts
    465

    Re: agitation -- tank vs drum

    I have three different agitation bases -- Unicolor reversing, Beseler non-reversing, and a Kindermann that rotates and lifts. In order the Beseler has (by far) the fastest rotation speed, followed by the Unicolor, and the Kindermann is last. A 15% reduction in time is a starting point, but a solid test would be my preference. I seldom use the Beseler, but I cut my time from the Unicolor (my standard unit) by around 10%.

  5. #5

    Join Date
    Jun 2006
    Location
    Westfield, New Jersey
    Posts
    417

    Re: agitation -- tank vs drum

    Just what I was looking for. Thanks all!!

    George

  6. #6

    Re: agitation -- tank vs drum

    I have just started using the Jobo recommended 5min pre-soak. This allows for standard inversion development times, or close to them. I like the longer processing times and so far so good. When I didn't pre-soak I would reduce processing time by about 15%, depending on rotation speed and developer, as a starting off point.

Similar Threads

  1. Which JOBO: Expert Drum (3006/3010) or 2521 tank
    By Ron Bose in forum Darkroom: Film, Processing & Printing
    Replies: 19
    Last Post: 18-Mar-2008, 11:30
  2. Uneven negs with daylight tank
    By jwarren116 in forum Darkroom: Film, Processing & Printing
    Replies: 16
    Last Post: 22-Feb-2008, 05:41
  3. 4x5 drum development questions
    By derek_5869 in forum Darkroom: Film, Processing & Printing
    Replies: 3
    Last Post: 14-Sep-2005, 16:32
  4. Agitation pattern for Nikor 4x5 tank
    By Arthur Nichols in forum Darkroom: Film, Processing & Printing
    Replies: 6
    Last Post: 11-Oct-2000, 01:34

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
  •