Above the lens filter drawer for Omega D2

Discussion in 'Enlarging' started by wskmosaic, Sep 25, 2012.

  1. wskmosaic

    wskmosaic Member

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    Does anybody have instructions how to construct a filter drawer for above-the-lens use on an Omega D2 enlarger?

    And does anybody have any insight as to whether or not it's better than the easier below-the-lens filter position? I'd hate to go to the trouble if it doesn't make any difference.

    tnx

    Warren Kornberg
     
  2. tkamiya

    tkamiya Member

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    Hi... I have two Omega D2, one with the variable condenser and another with fixed condenser but with a factory filter slot above the condenser.

    On both units, I actually use Ilford's below the lens filter bracket. Instead of attaching them to the lenses, I made a bracket and attached it to the lens plate that attaches to the bellows bracket. The consensus is that having filters below the lens makes no difference when compared to above the lens solution. I've been happy with my solution. It's really easy to swap filters without disturbing anything.
     
  3. wiltw

    wiltw Subscriber

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    The conventional wisdom is in the light path before the negative is far superior to being in the light path after the lens, where filter flaws can harm the image delivered to the easel. For example, gelatin filters were used below the lens and polyester filters were used above the negative, for that reason.
     
  4. wskmosaic

    wskmosaic Member

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    Both of those answers are helpful. Thanks. Do you know if the Ilford filters are gelatin or polyester?
    Warren
     
  5. wiltw

    wiltw Subscriber

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    If somewhat stiffer...polyester/acetate. Gelatin filters are very flexible and easily damaged.

    If filters have a labelled designation of 'CC' or 'CP', color compensating filters (CC) are used below the lens, and color printing filters (CP) are used between the lamp and the negative, according to Kodak recommendations.

    Variable contrast filters are generally quite rigid and are made to be used below the lens.
     
    Last edited by a moderator: Sep 26, 2012
  6. arpinum

    arpinum Member

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    Ctein's book, Post Exposure, went over this topic, iirc page 142. He found no differences in above the lens and below the lens filters. If one exists, he would have found it. The book is available free online as a pdf.
     
  7. tkamiya

    tkamiya Member

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    With logic and literature aside.... if I can see film grain on the baseboard clearly using grain scope and they are sharp, whatever the effect it might have on image must be negligible.

    I have no idea what the filters are made of....
     
  8. Bill Burk

    Bill Burk Subscriber

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    I have two sets of color filters that I wouldn't use under the negative.

    The better set is marked "Unicolor," and there aren't obvious image destroying qualities in that set other than scratches. The other set is only marked with the color values. This cheaper set, when viewed at an angle, reveals sort of a striped pattern like stretch marks in the base material. I wouldn't use either set in the D2.

    My multigrade filters, are hard plastic and clean and obviously designed to be used under the lens. So that's where I use them.

    But whenever I need longer enlarging time, I toss a two-stop No. 96 ND filter on top of the lens.
     
  9. wiltw

    wiltw Subscriber

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    The recommendations which I cited earlier are exactly what Kodak has in print in their manual about color printing on pp. 38-39, originally published 1984 and reprinted 1992 (ISBN 0-87985-662-9). OTOH also I know that back in the 1960's Kodak had Polycontrast hard filters designed for below-lens use.
     
  10. Paul Howell

    Paul Howell Member

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    If you have variable condenser D-2 6X6 filters will fit either over the top condencer in the lowe position, between the condensers in the mid position, and on to of the bottom condenser with the upper condenser removed. If you have the standard condenser I would use a set of Kodak polycontrast filter with holder under the lens. My perferance is use filters above the lens as dust is less likey to show.
     
  11. rjbuzzclick

    rjbuzzclick Member

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    This is what I've been doing with my D2. It works fine for my purposes.