On Wed, 22 Oct 2003 23:52:32 -0400, "Stephen Paul"
wrote:

Here's what I did:

1) Stand in front of mirror with measuring stick and get a read on the
outside diameter of my iris.
2) Take a picture of my eye in a darkened room using the digital camera set
SNIP...
I'm 44 years old.

-Stephen Paul


I tried a different method - probably not very accurate, though. I
cut a strip of paper about 8 inches long and tapered it from about 7mm
to about 3mm. Then I marked off the points at which the strip was
3,4,5,6 and 7mm wide.

Several times during an observing session last Friday, I held the
strip up to my observing eye and looked at Mars. When I moved the
strip up or down to the point where Mars blinked out, I pinched the
strip at the position in front of my eye and then looked at the strip
to see where I was marking it. The index marks indicated how wide the
strip was at that point.

The best I did was about 5.5mm but we had a pretty bright sky and
other stuff I was doing that prevented my getting fully dark-adapted.
I plan to try the same method at a really dark site to see how much,
if any, difference there is there.

Les Blalock
http://www.txastro.com