I guess you know the drill by now. Round earth with a moon whizzing around, and the pair occasionally block sunlight from each other. Neat stuff.
Do you want to see an actual ray diagram of that?
Well, I drew one in Adobe Illustrator, and then converted it to html.
Edit: WP Does not like custom headers in embedded html unless I pay.
Still, help yourself to a version of All-Star to make up for the blank background.
Anyway, enjoy. The ray diagram of a lunar eclipse, to scale, in PNG for now.