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Observing light from distance

  1. Feb 21, 2009 #1
    Which visible light frequency i.e red, yellow , green etc can be seen from greatest distance? and why?
  2. jcsd
  3. Feb 21, 2009 #2


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    Gold Member

    Welcome to PF, U2_wa.
    The answer to your question is primarily dependent upon who or what is doing the observing. Different sensors have different ranges of sensitivity to various frequencies.
  4. Feb 21, 2009 #3
    Yellow. I believe that's the human eyes' most sensitivity to "color"
  5. Feb 21, 2009 #4


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    Science Advisor

    Human eye sensitivity is actually peaked in the green, ~550nm.
  6. Feb 22, 2009 #5
    Thanks. I learn something new each day, especially here at PF!
  7. Jan 3, 2012 #6
    Some people perceive 550 nm as a greenish yellow/yellowish green.
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