Maule Driver wrote:

"Robert Lyons"

You all probably know about using pinhole viewers to see an eclipse.
You may also know that you can view an eclipse with a fragment of a
mirror, if it is small enough (or if you cover up most of a larger
mirror, leaving a small hole). It will project a perfect image of
the eclipsed sun on a convenient wall or floor. I'm pretty sure this
is what I was seeing from the air, projected on that flat haze layer.


A cute pinhole eclipse image I've seen was in a conference room with thin
slat blinds covering the windows. Every slat had two or more little holes
for string or something. Every holes shadow projected on the floor showed a
perfect little eclipse. There many dozens of them.




Yup - I've seen a similar effect with sunlight coming through
the canopy of a tree. Thousands of little eclipse images. The
holes have to be quite small relative to the size of the cast
image, in order to keep the projection in focus.

The in-the-air version I saw was similar, in that it didn't
work if we were passing over a larger lake. If the lake was
large enough for me to see it clearly, it was too big, and the
resulting image was distorted and out-of-focus. The lakes
that worked the best were barely visible to me - the tiniest
pinpricks of reflected light. That's what convinced me that I
was interpreting the phenomenon correctly.

- Bo