Koni Omega Rapid 100 rangefinder adjustment

Discussion in 'Medium Format Cameras and Accessories' started by altair, May 1, 2012.

  1. altair

    altair Member

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    Hi all. I recently acquired a Koni Omega Rapid 100 camera together with the 90/3.5 Super Omegon lens. Everything seems to be fine except for the rangefinder. The RF patch is contrasty & clear but it appears to be off, i.e when I focus on something via the RF patch, then check the distance scale, it tells me that the target is 8 feet away when in actuality it's more like 10 feet away!

    What can I do to rectify this problem? Is there an easy step-by-step walkthrough of what one needs to do to check & then realign the rangefinder? I haven't been able to find a downloadable repair manual. I'm not good with my hands though, all thumbs...but would try anything reasonably easy.

    Could it just be that my focusing knob is misaligned somehow?

    I haven't run a roll through the camera yet to check the focusing thoroughly and I haven't a ground glass or tracing paper handy.

    I'm in Malaysia, so sending the camera to Greg Weber is hardly an option.

    Would appreciate all feedback, thank you in advance.

    -Dani
     
  2. Barry S

    Barry S Member

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    Instructions here.
     
  3. MattKing

    MattKing Subscriber

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    I would check first to see whether the RF is actually correct - the focusing scale on the focusing knob is only relevant for scale focusing and the use of manual flashes.

    In addition, I would check that the focusing scale on the knob is the right one.
     
  4. ausphoto

    ausphoto Member

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    I would underline Matt's suggestion. Check that whether the RF is actually correct. Set up a test battery with camera on tripod and targets (chairs, people) at set intervals and focus on one ect..
     
  5. Konical

    Konical Subscriber

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    Good Morning, Dani,

    Temporarily tape a piece of waxed paper over the film plane; check to see if sharp focus there coincides with what the rangefinder gives you.

    Konical
     
  6. MattKing

    MattKing Subscriber

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    A picket fence makes a great focus target :smile:. Just shoot along the face of it so that different pickets are at different distances from the camera.

    Remember to bring a tape measure, some tape and some scraps of paper that you can mark with the different distances.

    And of course a tripod.
     
  7. altair

    altair Member

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    Thanks for all the replies, everyone.

    Barry, you're a lifesaver, thank you! I'll go through that instruction, and I'll do as it says pretty soon..I just need to get the right tools for the job first.

    MattKing: I've recently run a roll through the camera, all shot wide open and while I didn't shoot any picket fences (there aren't any here!), I can see from the photos that I got that the rangefinder is indeed off..the camera is front focusing by about 2-4 feet or so. Prior to that I had tracing paper stretched across the mirror box while the camera was on a tripod, but this method was iffy at best so in the end I decided to shoot a roll through it anyway. As for the focusing knob being the correct one, I can't tell.

    Konical: And a good day to you, Konical :smile: See my reply to MattKing above. Did the waxed/tracing paper method but found it to be iffy, I couldn't be sure if the paper was stretched tightly at the exact same plane as the film plane. Thanks for the suggestion, however...
     
  8. MattKing

    MattKing Subscriber

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