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  1. #1
    Shiny's Avatar
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    Levelling problem

    the only way i can get 6x4.5 negatives sharp across the whole negative is to tilt the enlarger head so that its no where even close to parallel with the baseboard, giving a warped print. The lens is in the head correctly and not stuck in at an angle.

    Could there be an element in the lens (75mm E Rokkor) that is out? I have never noticed this problem with 35mm negatives and a 50mm rokkor.

    Thanks

    Jim

  2. #2
    galyons's Avatar
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    Does this problem occur on all MF negs? Glass or glassless negative carrier? Glassless can let the neg "pop" creating focussing issues. Does stopping down help? Try the 75mm with a 35mm neg. It is unlikely to be the lens, but this would provide a cross check. These are factors to check first.
    Cheers,
    Geary

    Quote Originally Posted by Shiny View Post
    the only way i can get 6x4.5 negatives sharp across the whole negative is to tilt the enlarger head so that its no where even close to parallel with the baseboard, giving a warped print. The lens is in the head correctly and not stuck in at an angle.

    Could there be an element in the lens (75mm E Rokkor) that is out? I have never noticed this problem with 35mm negatives and a 50mm rokkor.

    Thanks

    Jim
    But your flag decal won't get you into Heaven any more. They're already overcrowded from your dirty little war.
    Now Jesus don't like killin' no matter what the reason's for, and your flag decal won't get you into Heaven any more. – John Prine

  3. #3
    wilsonneal's Avatar
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    I have a similar mystery with my D2. I bought the Omega leveling tool, and the baseboard and neg stage are perfectly aligned, and the neg looks square on the easel, but it's not sharp edge to edge.

    Neal

  4. #4

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    If the baseboard and the negative stage are parallel planes, then you have three other variables:

    The lens axis must be perpendicular to the negative plane. You can get errors here if the lens is held with a retaining ring and not a threaded mount, or you cross-threaded the mount. If you are swapping lenses on lensboards, the board itself could be warped or failing to engage in the chassis correctly.

    The lens could have a displaced element. I would be surprised that you could correct for that with a simple tilt of the head.

    A displaced condenser or mirror can have some odd effects. Usually just illumination issues though.
    I feel, therefore I photograph.

  5. #5

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    One other point (I hate following up on my own posts) - make test prints on each size using the 'wrong' lens. The 75mm should be fine for the 35mm frame, though the 50mm will be stretched on the 645. It should be good enough to see if the problem is the format or the lens/mount.
    I feel, therefore I photograph.

  6. #6

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    Check your easel. I once had an easel that was out of level.
    Art is a step from what is obvious and well-known toward what is arcane and concealed.

    Visit my website at http://www.donaldmillerphotography.com

  7. #7

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    Now there's a thought. And the 50mm would give a little more depth than the 75mm at a given aperture and mask the effect.
    I feel, therefore I photograph.

  8. #8
    Shiny's Avatar
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    Thanks, im checking everything i can. The image is perfectly square on the baseboard, it looks a lot better with the 50mm lens, but that doesn't cover the whole neg. I may try a cheap 80mm just to see if its the lens. The mount looks fine - condenser etc all level.

    Its a glassless negative carrier (durst F60) but im fairly certain i've got the negative dead flat. To get the image sharp edge to edge i would have to raise the right side of the easel by more than an inch which seems a lot.

    I may just have to stop right down for the time being.

    Thanks

    jim

  9. #9

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    Dear Jim,

    I don't know what sort of enlarger you have, but on my Omega you must also align the lens to the baseboard.

    Neal Wydra

  10. #10

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    Quote Originally Posted by Shiny View Post
    ...but im fairly certain i've got the negative dead flat. jim
    I've aligned my Omega B8 using a surface of the
    negative carrier. IIRC the top surface. No negative.

    The B8, a 6x9 D2, has both lens and negative stage
    provisions for alignment. IIRC, I first squared the
    projected outline of the negative carrier then
    began a lengthy balancing of adjustments
    of negative and lens stages.

    There are alignment tools of the point to point
    type. They may or may not affix to a surface
    which represents the actual film surface.

    The proof of perfect or near so alignment is
    the projected image. Dan

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