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Thread: Slit pinhole.

  1. #1
    500+ Posts Isis's Avatar
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    Slit pinhole.

    Going to make a single slit "pinhole" camera. Im thinking that you set the width of the slit like normal, ie .3mm at 45mm but the f stop is worked out on the area. Is this right, or how do I work out the f stop.
    Regards Shane
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    http://www.ipernity.com/home/isisford/
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  2. #2
    Exposure is determined by the area of the pinhole or slit.

  3. #3
    500+ Posts Isis's Avatar
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    Thanks Jim. Am i correct in thinking that the slit width is the same as the diameter of a pinhole for a given film to pinhole distance?
    Regards Shane
    - Suggestions on how to improve image always welcome
    http://www.ipernity.com/home/isisford/
    http://www.flickr.com/photos/isisford/

  4. #4
    Hi Shane,
    If it were me I would use the width of the slit to determine the f number, then reduce by X number of stops, X being the number of times longer (minus 1) the length of the slit is to the width.
    Example: slit 3 times longer than wide - reduce by 2 stops.
    (This also agrees with Jim on the 'area').
    Also, I would go with what you said about optimizing for the slit width.
    Last edited by Jimmy G; 05-21-2015 at 10:56 AM.

  5. #5
    500+ Posts Isis's Avatar
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    Thanks Jimmy, and that 6x6 your building looks stunning.
    Regards Shane
    - Suggestions on how to improve image always welcome
    http://www.ipernity.com/home/isisford/
    http://www.flickr.com/photos/isisford/

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