This Instructable is about a lens out of an old TV that I found in a thrift store. I have seen Instructables like this on line and wanted to test it out. It works very well.
I found a TV lens in a thrift store and an old quilting frame in another one. used some duct tape to hold it on.
I set a metal plate on a brick and put a cast iron skillet on it. It was smoking hot in minutes. I threw in some egg beater and had an omelet. Later I made a turkey chili. Both came out good.
To test heat I put an aluminum can in a ladle and focused the heat on it. I melted the can but would not turn molten in the ladle. Not bad heat source for almost nothing. CAUTION if you try this be very careful as it can cause major burns. I caught my lawn on fire. also wear sunglasses as it is very bright.