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Given on a clear sunny day, the only light that is blocking the star light is the scattered blue light of atmosphere.

If we make use of a notch filter, which blocks only the blue light, can we get to see the stars? Will the sky turn black and give us a feel as if there is no atmosphere?!

Or is the atmospheric scattering spread across a wider spectrum that a filter to block the scattering light ends up blocking most of star light too?!

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    $\begingroup$ Considering that the sky is typically pale blue rather than a deep blue, I expect that all visible wavelengths are present and quite bright. Biased towards the shorter wavelengths but not restricted to them. $\endgroup$
    – badjohn
    Commented Nov 24, 2018 at 9:05
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    $\begingroup$ Worth reading? $\endgroup$
    – Farcher
    Commented Nov 24, 2018 at 11:25
  • $\begingroup$ see this skysurfer.eu/daystars.php $\endgroup$
    – anna v
    Commented Nov 24, 2018 at 12:15
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    $\begingroup$ A polarizing filter might also help. $\endgroup$
    – user4552
    Commented Nov 24, 2018 at 15:41
  • $\begingroup$ @BenCrowell so, a filter and a polariser it is! The hunt begins for the duo! $\endgroup$
    – karthikeyan
    Commented Nov 24, 2018 at 18:14

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Here is the range of blue cone reception in frequncies, and then it is the biology of color perception that takes over:

The graphic below is a sensitivity curve that depicts the range of wavelengths and the sensitivity level for the three kinds of cones.

enter image description here

colper

The filter you propose seems to cover (430-500nm)

That leaves a lot of blue sensitive perception free, so I would guess no, it would not work.

Here is the content that gives the blue of the sky in frequencies :

blue sky

A spectrum taken of blue sky clearly shows solar Fraunhofer lines and the atmospheric water absorption band.

Nevertheless, if you have access to such a filter ,why don't you try, on a clear day? or put it on a camera and take a picture in daytime?

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  • $\begingroup$ I wish to! If I get hands on some filter, I will! What will be the spectrum of the scattering from the atmosphere? Is it as continuous as sun’s? $\endgroup$
    – karthikeyan
    Commented Nov 24, 2018 at 12:53
  • $\begingroup$ see my edit above $\endgroup$
    – anna v
    Commented Nov 24, 2018 at 13:00
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    $\begingroup$ The spectrum of blue sky peaks well below 500nm. The spectrum you show appears to be the spectrum of sunlight. $\endgroup$
    – ProfRob
    Commented Mar 8, 2023 at 8:54

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