So I ordered a package of wallet sized Fresnel Lenses from Amazon. If the sun ever shows itself again, I'm going to see how these work for fire making. As magnifiers, they work fairly well with one eye closed. When we got rid of our shop, I forgot to take the stack of giant Fresnel lenses we had stashed behind a workbench. They were the lenses we took out of the rear projection big screen TV's when we recycled them. Those things were dangerous. They would melt the asphalt in our parking lot...
Fresnel Lenses
Fresnel Lenses