Starting a Fire with a Fresnel lens – Step By Step

Starting a fire is one of the most rudimentary basic activities that a survivalist/prepper must be able to do. Whether for cooking, warmth, light, or protection – building a fire is critically important.

One method of fire starting I have utilized over the past year is the Fresnel lens. Basically a large magnifying glass – the Fresnel lens can gather the suns light and focus it to a very small and intense spot  – generating tremendous heat.

fire started with Fresnel lens
fire started with Fresnel lens

No doubt many of you as kids used a magnifying glass to catch some leaves on fire – this lenses works much the same way.

Why do I like the fresnel lens so much? Here are a few reasons:

  • cheap
  • durable and flexible
  • lightweight
  • simple to use

I have a couple of these in packs just shoved in behind something. So light and easy to carry. Of course – you need sun in order to use them.

I took a few step-by-step pictures to show what they can do…

A couple of my 7″ x 11″ lenses:

two Fresnel lenses

Prepared “dry stuff” to burn:

dry twigs

Showing “hot spot” from sun through Fresnel lens on rock:

sun shining on rock through Fresnel lens

Hot Spot moved onto tinder – see the smoke?

smoke starting to come out from tinder

We have fire!

Super-flexible and durable:

Fresnel lens in hand

The day I took the pictures the sun was shining bright and it was in the 60’s with a decent breeze. I had no issues at all get a roaring fire going. Obviously there are limitations to fresnel lenses – but they are certainly an option to consider in your preps.

The lenses I like are sized 7″ x 11″ and are super cheap. The are many other sizes available as well – even as small as credit cards.

Love sitting next to a hot fire on a chilly night –


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7 thoughts on “Starting a Fire with a Fresnel lens – Step By Step”

  1. I have a small credit card sized one that I carry in my wallet all the time. I am going up to the mountains today and I will start my fire with it just to practice my fire skills. I really like these things too. Great post Rourke. Keep the info coming.

  2. My credit union gave away small magnifying lenses that fold into a little protective case. I included one in my basic kit for this purpose and for use to magnify my vision when it is needed like when extracting a splinter. I have one of these larger fresnel lense and I love it. But I use it in the back window of my motor home where I think it serves it’s best use.

  3. I’ve never seen those lenses before, but they seem like they would be really useful. I like that they are really light weight and flexible so you can throw them in your pack and forget about them unless you need them. They’ll definitely warm things up.

  4. Hey Rourke! Hope you had a great Thanksgiving!

    I’ve seen these lenses before but would never have thought to use them like this. I actually have a couple somewhere in a box of books (you remember them…the kind with paper pages and bindings…gotta love the Kindle). I’m going to dig the lenses out and give it a try. Thanks!


  5. This is a great idea, like the post I read this morning, it’s the small stuff. Reminds me of the things we did as kids with a magnifying glass, you know starting fires and, well burning ants. I am going to add these lenses to all of my BOBs immediately. Thanks for the article.


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