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Inspire's own shadow...

Discussion in 'Inspire 1 Discussion' started by Mark C, May 19, 2015.

  1. Mark C

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    The footage I get from the inspire when filming its own shadow, whatever the distance to the ground or distance into the shot shows up as white "bloom spot" on the ground.

    I obviously try to avoid it but sometimes it happens...

    Anybody else notice this or is it just me?
     
  2. The Editor

    The Editor Moderator
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    It is know as the opposition effect.
    It is not something that is unique to cameras, our eyes see it as well as it's just physics. It happens all the time but is only noticeable in certain situations - mostly on uniform crops due to the texture of the subject and acute angle of the crops causing reflected light to go off axis from our view point but is also viewable on other surfaces.
    As light travels in straight lines (for the purposes of this phenomonen anyway) what we see in the world is made up of reflected light. (We Don't actually see any objects at all, only the light reflected from them)
    In this scenario, when we view the surface from above with the sun directly behind and at the same angle most of the light is reflected at angles off the surface which means what you see is very slightly darker. The bright spot is the light reflected in exactly the same plane as your viewpoint and angle and therefore very little of the light is lost in shadow/reflection. This then appears as a slightly brighter area from our viewpoint.
    It's not JUST crops though, it happens on nearly all surfaces.
     
    #2 The Editor, May 19, 2015
    Last edited: May 19, 2015
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  3. Jimmyholster

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    I have read about a dozen articles on the opposition effect, and your one post has helped me understand it infinitely better. Thanks very much =)
     
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  4. The Editor

    The Editor Moderator
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    My pleasure - I love armchair physics :p
     
  5. Jimmyholster

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    You definitely have a knack for explaining them =)
     
  6. Mark C

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    Ed....that is without doubt the most straight forward and factual answer I have had from any question I have asked on a forum anywhere, anytime....thanks, I am now enlightened.
     
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