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  1. #1
    stradibarrius's Avatar
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    IR reflection from snow???

    I know that green leaves etc. give the IR effect that we think of in IR shots. Does snow reflect the IR in sunlight???
    "Generalizations are made because they are generally true"
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  2. #2
    AgX
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    The reflectivity of snow depends to some extent on internal reflection within the snow.
    Water has a higher absorbance for IR than for visible light. Now it depends to what extent the light is not only reflected by the snow crystals but also transmitted. The more bulk the snow particles get, the greater their filtration effect becomes.

  3. #3
    jp498's Avatar
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    I haven't shot snow with IR film, but with IR digital it looks fairly natural. See the foreground here:
    http://www.f64.nu/gallery2007/view_p...73&id=DSC_0022

  4. #4

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    jp498 - sky looks kinda light for IR in your linked shot - what is IR Digital?

  5. #5

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    A digital camera with the IR filter removed or disabled.

  6. #6
    AgX
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    A digital camera with the IR-blocking filter removed is just a panchro-camera plus IR. So the IR radiation is added to the visible wavelenghth. In film photography the blue or even panchro sensitivity is still that great that in typical cases you have to block that by means of a IR-only transmitting filter.

  7. #7
    Sirius Glass's Avatar
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    Quote Originally Posted by photomem View Post
    A digital camera with the IR filter removed or disabled.
    You need to add a red #25 or #29 filter to take out the panchromatic portion of the visual spectrum.

    Steve
    Warning!! Handling a Hasselblad can be harmful to your financial well being!

    Nothing beats a great piece of glass!

    I leave the digital work for the urologists and proctologists.

  8. #8
    jp498's Avatar
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    They (lifepixel) remove the IR blocking filter, then put an IR filter over the sensor so it's real IR to the sensor and full visible to the pentaprism. Check out lifepixel for more details.

    This pic shows why the sky is not dark; it was very very hazy.
    http://www.f64.nu/gallery2007/view_p...um73&id=ircomp
    Last edited by jp498; 01-07-2010 at 05:24 PM. Click to view previous post history.



 

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