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Thread: only see photo when looking straight at it?

  1. #1
    Join Date
    May 2018
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    56

    Default only see photo when looking straight at it?

    I need a photo to drastically dim or scatter light so it won't be visible or barely visible when viewed from an angle.

    I had read that a lenticular lens film would do the trick but it appears to have no effect other than introducing rainbow fringes. But maybe the lenses are too small.

    There are privacy filters for monitors but only start dimming after +-30 degrees from the front and dim anything behind them by about 50%. The angles are too forgiving for my use for the brightness loss they introduce.

    Any other options or what am I doing wrong?

  2. #2
    Join Date
    Nov 2008
    Location
    Cleveland Ohio
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    2,598

    Default

    cardboard painted black

    try two privacy screen on top of each other

    try polarized illumination with a polarizer on the sides you dont want an image

    curve the image inward plus priv screen

  3. #3
    Join Date
    Oct 2012
    Location
    Germany
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    Default

    ... there are "fiber-plates" with optical glass fibers or with black hollow fibers, some mm thick -- but don't know the max sizes and prices ... had only samples with some ten mm square size or diameter ...

    Viktor

  4. #4
    Join Date
    Oct 2012
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    Germany
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    ... on second thought -- the "fiber-plates" with hollow fibers should work better - here a sample with a longer tapered fiber-bundle (the "plates" were bigger in size and only around 8-10mm fiber-legth), what's showing the transferred image with an angle more than 20° to the sides.

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    IIRC with hollow fibers this was something like 5° max ...

    Viktor

  5. #5
    Join Date
    May 2018
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    Default

    Very interesting ideas!

    I've already ordered a privacy film but hadn't considered stacking it.

    I should also have some linear polarizer films stored somewhere I could test out. I don't have a clear idea on how a polarizer based setup would look like but I'll try to think of something interesting. Slits of polarizer films such as these sculptures on top of the frame could work I guess if they were angled to face the eyes from a specific distance rather than parallel to each other. https://www.youtube.com/watch?v=DM1RQj3B9Ho


    I could curve the frame inward but could you please explain what that would achieve?

    I also don't understand the painted cardboard idea.


    VDX, fiber-plates sound interesting. Never heard of them. What industry are they used in? I looked in google and some wholesale sites but only got carbon fiber plates in the results.

  6. #6
    Join Date
    Oct 2012
    Location
    Germany
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    Default

    ... I've seen them with optical glass fibers for (micro-)imaging or with hollow fibers for micro-filtration or x-ray-applications ...

    Viktor

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