A quick demonstration of the difference between a Spot Lens and a Linear Lens, both of which are used in big screen TVs. The punchline being spot lenses can do everything that a linear lens can, and much more. Much higher temperatures achieved with a spot lens.
The spot lens in this vid was taken out of the tv in this video    • Solar Fried Hot Dogs with a TV lens   at 1:15 into the vid. I can't remember the make and model, but you can at least see the type of console tv that it came out of.