I read the article but don’t have a clue how it works. This article is useless without pictures.
actually you need to be good at geometry and spatial visualation to understand without pictures. Being able to spell (me) might help. /sarc off
GREAT! Now someone is going to post Helen Thomas thanks to you!!!
Better explanation at http://www.azooptics.com/details.asp?newsID=6014
Thank you. I agree and I googled everywhere trying to get a pix of the thing. Is that a brand name or just a descriptive term?
A simple picture would have said more than all the words and searches.
Anybody know where I can see one?