Fresnel lens from Sony projection tv.

I finally get the lens out and separated from the tinted screen. I had this tv literally hanging around for a few years.
Preliminary testing was very promising producing fire within a minute at 36" in full sun. However testing was halted by a cloud. The spot it ignited on a pine 2x4 was almost 4 inches wide charring about 1/4" deep.
My initial tests started a 4" circle of flame on a pine 2x4 within a minute charring the top 1/4 " of the surface. Testing was disrupted by clouds that persisted for the next day...