"tom" wrote in message
...
I just tested my canon SD450 powershot on my cat.

The eyes came out a bizarre glowing green like from
a science fiction movie. I haven't tested the camera on
coins yet, but this shot has me thinking of returning the
camera.

It's perfectly natural. Cats have a colored retina that reflects light. (It
helps their night vision, among other things.) Humans don't...the red you
see in photos of human eyes is caused by the blood in our retinas. The color
of the reflected light varies among species, btw.

Just for fun, while we're sort of on the subject:

In the tale "The Invisible Man" the scientist who eventually makes himself
invisible experimented on a cat...the only part of the animal that remained
visible was the reflective portion of its retina. (It's called the tapetum
lucidum. That's the thing that we have as well, but isn't reflective. And
yes, I had to look it up again. g) They're like little mirrors, and the
cat went through some torment at the hands of local kids who chased it
around trying to figure out what those floating green things were. The irony
is that if the scientist had made himself invisible in real life, he'd have
been as blind as a bat. Light would never have fallen on his retina; it
would have passed right through it as it did the rest of the man's organs,
etc. No light absorption on the retina, no vision. Of course, if it weren't
for reflection we wouldn't see anything at all, so I just suspend my
disbelief and enjoy the story anyway.


I also found, while looking up tapetum lucidum, that not all cats have a
reflective one. Some Siamese cats don't have reflective tapetums, and their
eyes show red like ours in flash photos. I also read that some dogs have
blue tapetums...that would be a creepy thing to see. Anyway, it appears that
not only does the color vary between species but in the species as well.
Cool, if you ask me.