Need a giant Fresnel lens for a solar project? Here’s how to salvage one from a rear projection TV. You’ll get a nice mirror, too.
The Squirrel says: The Fresnel lens is basically a magnifier. Its design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design. A Fresnel lens can be made much thinner than a comparable conventional lens, in some cases taking the form of a flat sheet – as we see is the case inside the TV. A Fresnel lens can capture more oblique light from a light source, thus allowing the light from a lighthouse equipped with one to be visible over greater distances. It also means it’s highly suitable for DIY solar projects, like making a cooker.