Hiya Curly. I've got a Freznel lens about half the size of the one shown on the web site. It looks like a 1/8 inch thick piece of plexiglass with many concentric circular grooves cut into it.
...and I believe it came from an electronics and appliance store. It's intended use was to place it in front of a television set to increase the screen size when viewing.
Sort of a poor man's big screen TV, so to speak. I need to dig that thing out and see how well it works for TV viewing.
Dunno if I want to try using it the way those guys were. Sounds like it could damage your eyes the way they described it.
Les
