Survival Skills: Make Fire With A Fresnel Lens

The Fresnel lens was developed by a French physicist named Augustin-Jean Fresnel in the early 1800’s. It was a revolutionary way to make a thinner magnifying glass and it was originally created to magnify the light emitted from coastal lighthouses. Once branded "the invention that saved a million ships", over the years, the uses of this lens expanded beyond illumination into photography, projection, and solar power. Today’s Fresnel lens is typically made from flexible clear plastic, bearing the traditional concentric grooved circles that allow magnification. The most commonly available lenses are the size of a sheet of paper, but they are also available in small “credit card” sizes (perfect to tuck into your wallet, backpack or survival kit). Either of these sizes will work as an optical fire making lens, though the larger lenses work best. You will need full sunlight for best results (though it can work on a hazy day). You will also want a dark fluffy tinder material. I use fibrous pounded tree bark (tulip poplar being my favorite), but many plant-based tinder materials will work. Just keep in mind that darker colors will absorb light more effectively. When you are ready to make this optical fire, simply hold the lens up perpendicular to the sun’s rays. Adjust the distance from your tinder until you’ve created a blinding focal point of light on the tinder and watch the smoke begin to form. Blow on the tinder and flames should appear. 

Ready to learn some unconventional (and traditional) fire building techniques? My Ultimate Fire Starting class is the perfect place. Check out the course details for all the specifics.

Written by Tim MacWelch First draft published on outdoorlife.com