You have to learn how to start a fire no matter what. Not by using a pack of matches or a lighter. There are a few ways which can work, like using a magnifying glass.
We all know that the sun has The sun has a lot of energy but because it’s so far away, that energy is spread out in all directions. What you need to do is focus all that energy into a smaller spot. So gather some tinder, and get your Fresnel Lens in an angle to grab some heat. You don’t really need 100 Watts of energy on a spot to start a fire but you don’t want to go too small either because in real life, the Watts hitting your tinder are gonna be even less due to clouds, smog, the season changing the angle of the sun, how clear your lens is etc. That’s why the smaller lenses don’t always work in real life. In a survival situation, you need it to work.
What is a Fresnel Lens?
Fresnel lenses are really light and take up almost no space in your backpack. You could just slide it in where your water pack goes or inside against your back and are cheap.Move the fresnel sheet closer and farther from what you’re trying to light until the focused light spot is smallest, and then flex the sheet to make it as small as you can get it. The smaller the focused light is, the higher the density of light there is, so the hotter it will get. You’d want to have your kindling and the rest of your wood close by so it could catch before the leaves go out. In some cases, you’ll want to move the light around a bit to catch more of the leaves on fire, especially if you have clouds coming.