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Regarding Polarizer and viewing sun

  1. Apr 21, 2015 #1
    If two polarizers are placed 90 degree rotated to each other, we won't be able to see anything. But when I tried looking directly at sun, which I did only for a second, with that perpendicular pair of polarizers, I was still able to see the sun.
    Shouldn't the sun disappear too ? Or why is it am able to see the sun ? Similarly it's applicable when I look at a strong source of light, like tube light or CFL bulbs.
    Last edited: Apr 21, 2015
  2. jcsd
  3. Apr 22, 2015 #2


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    Staff: Mentor

    I expect that the polarizers are not perfect and let some small amount of light through.
  4. Apr 22, 2015 #3


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    Gold Member

    I think it is just imperfection in the polarisers. They seem to vary in quality, because those I have here will block ordinary light bulbs. To obtain the very high re
    First of all, may I mention that it is unsafe to look at the Sun through the polarisers because they do not reduce IR to a safe level.
    Regarding being able to see the Sun through them, polarisers are not perfect. I have found examples on the Net with "extinction ratio" from 0.5% to 0.005%. It is interesting to consider the nature of the small leakage. If it is linearly polarised, it will be possible to remove it by rotating the polariser very slightly. But if it is circularly polarised, then it will not be possible to remove it by rotation. This situation will happen if the film causes different phase shifts for the two linear polarisations.
  5. Apr 22, 2015 #4

    Andy Resnick

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    Excellent point- and UV light, as well.
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