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Thread: What caused this "half moon dot" in the attached photo?

  1. #11

    Join Date
    Dec 2015
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    Erie, Colorado
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    46

    Re: What caused this "half moon dot" in the attached photo?

    The only time we've seen the SP-445 film holders interfere with processing, is when the negative is loaded in backwards (we've had several customers admit to that.) That leaves very distinct vertical lines if they're using the original holders. Haven't had anyone do it (or admit it to us) with the new holders.

    Besides, Tom Wakefield (on the facebook thread) spotted it in another image of mine. I missed it, since it's on the white part of the church.
    Click image for larger version. 

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    Click image for larger version. 

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  2. #12

    Join Date
    Sep 2010
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    519

    Re: What caused this "half moon dot" in the attached photo?

    I have seen similar half moon-shaped defects on roll film due to crinkling the film when loading the reel, but never on sheet film. As you probably know, stressing the film can cause a build up of extreme density at the site.

  3. #13

    Join Date
    Nov 2015
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    Alberta, Canada
    Posts
    94

    Re: What caused this "half moon dot" in the attached photo?

    Are they on the negative Tim?

    Thanks
    Dave

  4. #14

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    May 2015
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    SooooCal/LA USA
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    Re: What caused this "half moon dot" in the attached photo?

    Check the neg carefully to see if there is something stuck to the neg, or a density spot (as this is white, and didn't allow light through the neg there)...

    You can also sell the image to the tabloids (or Ripley's) if you come up with a good enough story... ;-)

    Steve K

  5. #15

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    Dec 2015
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    Erie, Colorado
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    Re: What caused this "half moon dot" in the attached photo?

    Dave,
    Appears to be in the emulsion; part of the image.
    No dust, dirt etc.
    Might have it on another negative as well.

    Tim


    Quote Originally Posted by DHodson View Post
    Are they on the negative Tim?

    Thanks
    Dave

  6. #16

    Join Date
    Oct 2012
    Location
    Portland, OR
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    619

    Re: What caused this "half moon dot" in the attached photo?

    they both appear to be on the same part of the negative. curious... is there any part inside the camera that is shiny and could focus a bit of a flare somewhere?
    ~nicholas
    lifeofstawa
    stawastawa at gmail

  7. #17

    Join Date
    Sep 2003
    Location
    La Luz del Oeste, Albuquerque NM
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    506

    Re: What caused this "half moon dot" in the attached photo?

    Well, another thought:
    Quote Originally Posted by stawastawa View Post
    they both appear to be on the same part of the negative. curious... is there any part inside the camera that is shiny and could focus a bit of a flare somewhere?
    Both white 'blips'--on the shingles and next to the window--have the same shape and approximately the same orientation. Look at, for example, the upper right side of the blip: something like a curved 'cap' is in this quadrant of the blip.

    So I might go back to the camera, check for light leaks, problems with inserting film holders, etc.
    Peter Collins

    On the intent of the First Amendment: The press was to serve the governed, not the governors --Opinion, Hugo Black, Judge, Supreme Court, 1971 re the "Pentagon Papers."

  8. #18

    Join Date
    Dec 2015
    Location
    Erie, Colorado
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    46

    Re: What caused this "half moon dot" in the attached photo?

    I think I found the problem: there's a bubble in the lens! Of course, the bubble will move with the movements; so it shifts from one photo to the next. Never noticed this before; I guess you have to aim into the sun just right.
    Click image for larger version. 

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  9. #19

    Join Date
    May 2001
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    Switzerland
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    Re: What caused this "half moon dot" in the attached photo?

    No I do not beliefe your bubble theory, I have also an old lens with 2 bubbles but I didn't see something like this in my negs from this lens! Could it be that a tiny bit sunlight hit the front lens element! Is it a old uncoated lens?

    Cheers Armin

  10. #20
    Nodda Duma's Avatar
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    Nov 2014
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    Brookline, NH
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    Re: What caused this "half moon dot" in the attached photo?

    A bubble in the lens is as out of focus as the lens itself. The "aperture" diameter of the bubble is so small that it would be a shadow and not a spot of light. Bubbles in lenses create scatter, reducing contrast ever-so-slightly. They don't, however, create focused spots.

    I'd suggest checking for pinholes in your bellows.
    Newly made large format dry plates available! Look:
    https://www.etsy.com/shop/Pictoriographica
    .. because my wife is happy when I can cover my photography expenses!

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