Unicolor Drums

Discussion in 'Darkroom Equipment' started by seadrive, Feb 21, 2006.

  1. seadrive

    seadrive Member

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    Hi guys and gals,

    Can someone please tell me the difference between a Unicolor Film Drum and a Unicolor Print Drum?

    Several weeks ago, I bought what was described as an 8x10 Unicolor Film Drum. It has plastic rails on the inside wall, that allow you to process 2 5x7's or 4 4x5. To do 4 4x5's, you need one of those rubber separators that always seem to get lost. Since I use 5x7, I don't care about the separator.

    Today, I noticed an 11x14 Unicolor print drum on eBay. It says you can use it for 4 5x7's (assuming it comes with the separator). So I Google for "unidrum color print processor" (that's what it says on the box), and I find this:

    http://www.largeformatphotography.info/unicolor/

    where the guy clearly tells you to get the print drum, not the film drum, to process 4x5 sheet film.

    So... I'm confused!

    Why would there be a difference between the film drum and the paper drum? Don't they both have to keep smaller-than-maximum size sheets or paper from moving about in the drum? So don't they both need to have rails and separators??

    TIA!

    Steve
     
  2. Paul Howell

    Paul Howell Member

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    The film drum is used with plastic reels, it does not have the rail for sheet film.

    Paul
     
  3. Shinnya

    Shinnya Advertiser Advertiser

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    Hi,


    My understanding is that what you already a print drum, which some people use as a film drum when they process sheet films.

    The difference is that a film drum is meant to process roll films, either 35mm or 120. There are special reels for those tanks.

    Hope this helps.

    Warmly,
    Tsuyoshi
     
  4. Dave Swinnard

    Dave Swinnard Subscriber

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    The Unicolor film drum I have comes with reels for film but was intended for use on a roller base. One end seals with a liquid-friendly removable lid similar to any other film dev. tank, the other seals with a piston-like movable piece that is pushed up against the reels and clamped.

    This makes a film-reel chamber just as big as the number of reels you are using (1 to perhaps 4 or 6 in 35mm size, don't recall the upper limit). Each reel has a center piece that mates to the reel beside it forming a tube from the bottom of the reel stack to the top. Once loaded it is put on the roller base and processing commences. Liquids are poured in and out by removing the tank from the base and pouring.

    The drum you describe with the ridges I always thought of as the Unicolor paper drum. Intended initially to process color paper with very minimal amounts of chemistry (this dates from just after the days of the color-canoe). Mine is ridged as you say so smaller sheets of paper can be processed in a small amount of chemistry. I never used my paper drum for paper though, it was my first attempt at mechanizing my sheet film (4x5) processing. It was very useful for many years (1980 on until I finally splurged and got a JOBO expert drum and processor in 1999)

    The film occasionally would move enough to overlap slightly but I never had a big issue with it. There have been "developments' over the years by various folks that dealt with the film movement issues but it never plagued me enough to bother with. (the way the smaller sheets are located have them up out of the chemicals when the tank is positioned to add or dump chemistry. They are only in the chemistry while the drum is actually rotating and, if the tank is actually level as it's supposed to be, the film feels very little force in the direction of it's adjacent "slot-mate".

    Dave

    Dave
     
  5. seadrive

    seadrive Member

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    Thank you, one and all.

    Roll film, yeah, of course. I knew that, in a past life. Funny how, when you start shooting sheet film, you forget that anything else exists <sigh>.

    So, what I have is a print processor, not a film drum...

    Steve
     
  6. Paul Howell

    Paul Howell Member

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    In addition to Unicolor you can also use Besseler and Cibrichrome drums for film. I can fit 2 4X5 sheets in a Besseler or 1 4X5 in a 5x7 Cibra drum, but for the most I use rubber tanks.
     
  7. Konical

    Konical Subscriber

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    Good Afternoon,

    And don't forget the Chromega drum; the 8 x 10 size works great for four 4 x 5 negatives.

    Konical
     
  8. egdinger

    egdinger Member

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    I have a unicolor drum (8x10 size) that doesn't have the ridges inside... what was it used for?
     
  9. Nathan Smith

    Nathan Smith Member

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    If it does NOT have the ridges then it's a film drum, designed to hold roll film holders. The print drums have ridges to separate/hold the sheets of paper - and luckily enough, the ridges work just as well for sheet film.