Why do red color attenuate in water the most and in air the least?

vishnumanu

Hi, I am currently doing a project in underwater image enhancement. Just now i got this little question that came to my head. I know it sounds silly.
You could notice the red color of sun at sunset, this is due to light scattering and red is least scattered as compared to blue.
On the other hand, in water red scatters first whereas blue scatters the least. Why?
Whats the difference between air and water for this complete change of nature of scattering...?

vishnumanu

hi folks, i think this is connected with something about refractive index about air and water. But i still dont get any correct answer for this.. Please do reply rather than viewing this.

DrDu

Are you refering to the blue color of thick sheets of water? It is due to red being preferentially absorbed, not to scattering.

Drakkith

See here: http://en.wikipedia.org/wiki/Electro...Visible_region
And here: http://www.opticsinfobase.org/view_a...bile%3Dno&org=

vishnumanu

Thanks .. Although i didnt understand them completely, i think water has a special property which is explained by that graph...Right?

vishnumanu

Is it something related to energy difference between different color spectrum? like the blue light has lesser energy than the red one...

DrDu

Wikipedia has an answer:
http://en.wikipedia.org/wiki/Color_of_water
http://en.wikipedia.org/wiki/Electro...ption_by_water
Apparently the blue colour of water is due to absorptions by overtones of the vibrational excitations of the water molecules.