How do you deal with light leaks from Omega D2?

Discussion in 'Darkroom Equipment' started by tkamiya, Jan 14, 2013.

  1. tkamiya

    tkamiya Member

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    I have an Omega D2 and DII. I've been noticing, if I burn in my prints to some significant degree, parts that did not (intentionally) get exposed during this burning process gains some density. Obviously, stray light is exposing the covered part.

    On my D2 and I'm pretty sure everybody's D2 has the same problem. Mine is in very good shape with no obvious damage.

    There are some significant light leaking from where condenser meets the neg carrier. Also, there are some leaks from the lamp housing going straight up. I can tell this because there is a shape of vent holes projected on my ceiling.

    My walls are white except the part directly behind my enlarger. That part has black paper pasted on it.

    This is a very common enlarger with a long history of extensive usage by professionals. Are there common modifications or treatments done to this enlarger to prevent stray light exposing paper? I'm looking for "best practices" with this gear. Can anyone help me?
     
  2. Dan Henderson

    Dan Henderson Member

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    I closed small light leaks in my D with bits of black gaffer tape. I mitigated to the degree possible the leaks around the negative carrier by taping pieces of black mat board onto the sides and back of the light source, letting them hang down past the carrier and at least keeping some of that light from bouncing around. Some light still leaks out the front of the negative carrier but it has been greatly reduced. I also refrain from wearing a light colored shirt when printing to avoid bouncing leaking light onto my paper.

    By the way, I use a cold light head so heat from the bulb is not a concern with blocking vent holes and taping combustibles onto the light source. If you are using a condenser head remain aware of heat transfer to paper or mat board, and especially when blocking up holes that might otherwise dissipate heat from the enlarger bulb.
     
  3. Ken Nadvornick

    Ken Nadvornick Member

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    One standard solution is to cover all of the nearby walls and ceiling with black. Either paint of matt board.

    But like Dan I also use a cold light head. So I've been considering simply going to a fabric store and purchasing a yard of lightweight, tightly-woven, black cloth. Something smooth, like silk, but less expensive. Then cutting it square and draping it over the head during exposures such that it hangs down a little below the negative stage. Simple, easy to do, and probably overkill.

    I've also figured this piece of cloth could then do double-duty as a lightweight drape over the bellows of my 8x10 when the sun is shining. (Not that that ever happens in the Seattle/Puget Sound region.) Sort of the inverse problem.

    Ken
     
  4. Jim Rice

    Jim Rice Member

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    I had a D-II with both the condenser head and the old acetate Chromega. The Chromega had better provision for mitigating light leaks at the head/carrier interface, but both heads leaked enough to be of concern. My D-5 seems to have corrected most of these problems but I will not fully know for a couple of weeks until I get her really set up. If I were to dive in on baffling I would start with some brass shim stock (k&S) from your local hobby shop and some black spray paint.
     
  5. Jim Rice

    Jim Rice Member

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    And jeweler's saws, pin-vices and files.
     
  6. PKM-25

    PKM-25 Member

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    Black gaffers tape and Duvetine black out cloth with Velcro to hold it in place, on my 45 MX that is...
     
  7. Jim Rice

    Jim Rice Member

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    All pretty cheap but it does require some (easily acquired) skills. Cut templates from cardboard for the design stage and testing and brass for the implementation.
     
  8. Jim Rice

    Jim Rice Member

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    Though I think its a losing game when cheap improved chassis are available.
     
  9. jordanstarr

    jordanstarr Member

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    ...turn off all your safelights and everything...throw something opaque in the carrier (black electrical tape?) and see where light is hitting your easel. You can move your hands around to see where the light is reflecting. You might have to sit in the dark for a few minutes for you eyes to adjust. That's how I found mine and now I have a black sock on my column.
     
  10. Ken Nadvornick

    Ken Nadvornick Member

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    Another very simple mitigation for the head/carrier interface is to go a hobby shop and get a sheet of adhesive-backed black felt. (It's not real felt these days, but just as good for this use.) Then use your trimmer to cut a long strip about 1/8th inch wide. Take that strip and stick it all the way around the underside rim of the condenser housing (this is also where the round cold light cans reside).

    The effect is that when you lower the head directly onto the carrier top, the felt seals up the slightly imperfect fit very effectively. On my D5XL there is absolutely no leakage from this location. And a nice side effect is that if you're equipment-anal like me, the felt prevents any marking up of your nice clean carrier tops, especially if they're white enameled.

    And again for the inverse problem, I've used this same felt to seal up the interface between the camera body and bellows mounting frame on my 8x10 (a like-new restored Calumet C1). Had light leaks before. Has absolutely none now.

    Ken
     
  11. tkamiya

    tkamiya Member

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    I have some foam tape. I'll try that all around bottom of the condenser. Thank you.
     
  12. artonpaper

    artonpaper Subscriber

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    I use that spongy with the peel of backing. I think its insulation tape. I taped so it hangs down a bit from the head and compresses against the negative carrier when the head is lowered in position.
     
  13. Bill Burk

    Bill Burk Subscriber

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    Thanks Tkamiya for asking and Ken this sounds like a good idea.

    When I used my Omegalite, there was a spongy foam interface between lamphead and negative carrier. I modified this sticky foam by covering it with some thin black 1.1 silnylon (leftover from some DIY backpacking gear projects).

    But I recently switched to an Aristo Grid lamphead which uses a traditional condenser housing. I noticed that greenish light spilling out pretty dramatically... So I am looking for this same idea. Didn't want to use "felt" because I didn't want dust. But this is exactly what I was thinking would be required.
     
  14. Ken Nadvornick

    Ken Nadvornick Member

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    From my own experience another nice side effect of the fake felt is no dust.

    Since the fibers themselves are some sort of plastic, they don't fray and break off. And because they are affixed in a strip compressed directly between the condenser and carrier, they are completely covered when the condenser is in the lowered position, which is how I keep it when not in use to keep airborne dust out of the bellows. Thus they gather no dust themselves.

    And finally, because they are in a compressed state during all of the downtime, the adhesive stays firmly attached to the bottom ridge of the condenser housing. Yet because they're plastic, when you do lift the head they spring right back up. And I'm also pretty anal regarding dust in my darkroom, as I routinely use double-glass AN negative carriers for optimum sharpness.

    I did try the adhesive weather stripping. But even using the thinnest I could find it still wedged the cold light diffuser up too far up from the negative. Then I tried attaching the stripping all the way around the outside of the condenser, with only a thin portion protruding below the bottom to act as a seal. But the adhesive, being subject to a constant lateral (vertical) force relative to the sticky surface plane, constantly popped off. And the new, larger circumference was too large for my standard carriers, which the condenser housing just barely covers.

    Ken
     
  15. jnanian

    jnanian Advertiser Advertiser

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    i sometimes put glass plates in my durst 601 head ... without a negative carrier and light spills and leaks everywhere
    what i ended up doing was taking a piece of cloth and taping it above and below where the light is leaking.
    cheap and easy ...
    have fun !
    john