Elf, as far as I know, this "trick" involves using a large lens to project a TV's image at a screen.

I can't imagine that the picture is very bright, as the amount of light that is emitted by a 19" TV would have to be spread out to a 100" size.

They usually forget to mention that you have to go inside the TV and re-wire the coils on the neck of the CRT to reverse the horizontal scanning direction.

Larry
www.fineelectricco.com