Re: InfraRed and Water - A comprehensive approach - Final Chapter

["Charles Andrew" <candrewpsu@xxxxxxxxxxxxx>]

----- Original Message -----
From: Editor - P.O.V. Image Service <editor@xxxxxxxxxxxxxxx>
To: <infrared@xxxxx>
Sent: Wednesday, March 22, 2000 7:22 PM
Subject: re: InfraRed and Water - A comprehensive approach - Final Chapter


> Our final chapter opens as..
>
> Rolland Elliott wrote:
>
>
> > Given these facts it is very
> > unlikely that any photographer shooting IR film will ever have to be
> > concerned or compensate their exposure due to the IR absorbence of water
> > unless they are doing underwater IR photography (with distant subjects)
> > which is virtually non exsistant.
>
> Wrong.. Wrong.. Wrong...
>
> The more water vapor the less Near IR in a ratio to visible light!
>
> And don't talk about red sunsets and sunrises here... That goes back to
> refraction and scattering by particulate matter in the atmosphere... At
> the
> extreme incident angle of a sunrise or sunset, that scattering
> overwhelms,
> finally, the absorptive qualities of water vapor..  Talk to any long
> term photog
> and they can tell you that the most beautiful sunsets are in dry dusty
> conditions
> where there is increased suspended particulate matter in the
> atmosphere....  The
> residents of Puerto Rico, for example, enjoy their most beautiful
> sunsets when
> the trade winds blow African Sahara dust across the Atlantic..  And
> desert
> sunsets are most beautiful in windy conditions where more particulate
> matter is
> kicked up into the air..
>
> >
> >
> > Whew, Rolland.
>
> My words exactly...!
>
> Whew Rolland... Got it now?
>
> I apologize to all for the length of this post, but we don't need to
> banter on
> about this.. The simple fact is H2O is IR absorptive AND the surface of
> a body of
> water will remain IR reflective from many incident angles..  Any IR that
> penetrates the surface will be quickly absorbed by the water.. If that
> were not
> so, the only option would be for IR to bounce around in a pond or
> seawater until
> it hit a rock or some other object...  If that were true, you would see
> the
> interior of a body of water in a Near IR image: fish, rocks, the
> seafloor, all
> would be visible... It just doesn't work that way in reality...  In
> fact, if you
> want to see through water, concentrate on the blue and UV rays of
> light....
>
> Given your comments on aquaria, etc... I can bet that as fish develop in
> the near
> absence of IR, that imagery of aquatic fish, plants, and other animals
> shot to
> show UV and Blue differentiation would prove way more interesting than
> UV imagery
> of said-same items..  Adaptive evolution would lead aquatic dwelling
> living
> things to adapt coloration that could be seen by other denizens of the
> watery
> realm...  Although with IR and a limited amount of water you might get
> some
> nicely translucent appearing aquatic denizens in certain instances...
>
> Keith Krebs
>
> --
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> {          nor, should they be understood to represent the            }
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