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

["Charles Andrew" <candrewpsu@xxxxxxxxxxxxx>]

HI!  I am interested Keith Krebs comments that "in fact, if you want to see
thru
water, concentrate on the blue and UV rays of light...have there been any
photos of
humans that are more that surface shots using this type of light considering
that they
are mostly water?  I suppose the answer would be no or it would be used in
medicine.
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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