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Primary Colors of Light

  1. Apr 19, 2007 #1
    Hey, I'm trying to make three LED lights that each are one of the primary colors of light. But, after discovering real fast that Radioshack doesn't sell the right kind, I asked my physics teacher for help. He said I need to go out and find the wavelengths of the three colors. And here I am! So, the question is: What are the wavelengths of the primary colors of light? I feel like I should be able to find it online but I'm having some trouble. Thanks.
     
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  3. Apr 19, 2007 #2

    berkeman

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  4. Apr 19, 2007 #3

    chroot

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    Also, tri-color LEDs are pretty common. These devices have three LEDs integrated into one small package.

    - Warren
     
  5. Apr 19, 2007 #4

    Claude Bile

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    There is no specific wavelength corresponding to each primary colour. This is because the response of our eyes is spectrally broad. You are more likely to be restricted by the LED wavelengths available - I think something between 420-480 nm would be fine for blue, 500-540 nm for green and 600-700 nm for red.

    Again, there are no specific wavelengths we define as being a primary colour.

    Claude.
     
  6. Apr 19, 2007 #5

    chroot

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    Actually, there are. The pigments in our eyes have peak sensitivities at specific wavelengths.

    - Warren
     
  7. Apr 22, 2007 #6

    Claude Bile

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    Sure, but the peak sensitivity for the red cones is at 564 nm, which is quite yellow. It therefore doesn't make sense to define primary colours on this basis.

    Claude.
     
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