On Fri, 30 Jul 1999 03:54:49 -0500, Mike <Ama### [at] aolcom> wrote:

>The effect is real.  It's more noticable if you are on higher ground
>looking down on the water.  I put an example in binaries.images.
>
>-Mike

I will say that I have noticed that it's harder to see into a body of
water when viewing at a small angle. As for the brightness of the
surface reflections themselves, they always seemed relatively constant
to me. 

Now the proportion of surface reflection intensity vs. the intensity
of light transmitted through of a body of water will certainly vary,
but the only variance that I can see is in the transmitted rays of
light. I might be wrong, but I believe a similar principle is at work
here as in fiber optics. At some point, there is probably total
internal reflection of the light from under the surface and images
from the bottom don't reach the viewer's eye, at least in the case of
very small angles of view. POV-Ray might already handle total internal
reflection effects, but I don't know for sure.

As for the image you have posted, I am left wondering what sort of
material is on the hillside above the rocks. By any chance is the
hillside a darker color than the rocks? That would explain the darker
reflections closest to the viewer. As for the stick's reflection being
dimmer, it seems the stick is not as bright as the rocks to begin
with. I also think that since the stick is so slender an object, that
it's reflection in the perturbed surface of the water would have some
"holes" in the reflection. That is to say, since the reflecting
surface is perturbed, some of the areas where you would expect to see
the reflection of the stick, are actually reflecting some other nearby
object instead. In the case of the rocks, they are a much larger area.
It would take much more surface distortion to "lose" the image of the
rocky area. Instead of parts of the warped surface reflecting an
object other than a rock, it is simply reflecting light from a
different rock instead and the overall brightness is about the same. 

Later,

Glen Berry

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