Fresnel Lens

The Fresnel lens received its name from French physicist Augustin-Jean Fresnel who developed the compact lens for use in lighthouses.

Fresnel lenses can shine through thick fog layers.

This is mainly because they can capture light coming from a lamp and magnify it, steering it in one direction.

They can also be used as car headlights, solar concentrators, fire starters, and lights at huge outdoor events to make the place more bright and beautiful.

Also, due to their availability in large numbers, their low weight, and low cost, they can be a perfect option for optical communication.

What makes Fresnel lenses different from conventional lenses is that they are much thinner, and they can even be formed into a flat shape.

They consist of various angled segments, unlike other lenses with only one large arc. 

Today, these small, flat, compact lenses are usually produced to resemble a credit card's shape, making them ideal for survival kits.

The concept is pretty simple.

Fresnel lenses are flat on one side, and the other side contains several small ridges, which are rings to focus the light towards the middle. 

The design allows you to gather light from the sun and focus it into a small concentrated beam that can be hot enough to light a fire under the right conditions.

What Materials Are Used To Make Fresnel Lenses?

Fresnel lenses can be made from different materials.

Makers can use vinyl, polycarbonate, or an acrylic substrate, depending on the operation’s wavelength.

Credit Card Size Fresnel Lens Fire Starter

In harsh conditions, polycarbonate is preferable because it is resistant to high temperatures and any impact.

In most cases, though, acrylic is the preferred material to make Fresnel lenses because it is perfect for transmitting light in ultraviolet regions.

The Advantages Of Using A Fresnel Lens

Some of the advantages include:

They Are Portable

In addition to the various uses of Fresnel lenses, they are very portable.

They are commonly referred to as a credit card magnifier.

Their lightweight, compact design allows you to place them in your wallet, tackle box, or anywhere else you desire.

You can choose to carry a credit card magnifier instead of a business card if you are going for outdoor activities.

That way, you can start a fire whenever you like as long as you have dry tinder and bright sunlight.

They Are Cheap

They are affordable. 

You can purchase one for roughly $1-$2, and they are available online or in many outdoor department stores.

After buying one, you don’t need to purchase any batteries, and it hardly wears out.

You can use it as many times as you like because it has no expiration date, making it very economical.

Simple to Use

It is very easy to use, and you do not require so many things to start a fire.

As long as the sun is bright and you can get dry tinder, you are good to go.

They Are Versatile

You can use your Fresnel lens to view far and smaller objects.

That is why it is commonly used in evaluating detailed maps.

In some cases, people even use it to see clearly since it can serve as a magnifying glass.

Most models have a 2x or 3x magnification.

Although 4x or even 5x models are available, making starting a fire a little easier.

What Are Some Of The Disadvantages Of Using A Fresnel Lens?

The biggest disadvantage is they're dependent on the sun’s availability.

Since these lenses require the sun for operation, they only work on a sunny day, preferably when the sun is at its highest point. 

So, on a cloudy day or at night, they're pretty much worthless.

Since they're not very reliable in all conditions, you should never choose this type of fire starter as your primary survival fire-starting tool.

However, it is a great addition to any survival kit, and it can be a fun and entertaining way to light a fire.

How To Start A Fire With A Fresnel Lens

It is good to know more than one method of starting a fire so that you can use the other when one way fails.

If you know the concept of creating fire with a magnifying glass, using a Fresnel lens won’t be difficult for you.

As when using a magnifying glass, you need to focus the sun’s rays on a specific light point.

So, assuming you are attempting this on a sunny day, start by gathering a supply of dry grass, pine needles, and small sticks to use as your tinder bundle.

For best results, try to line up the sun, lens, and tinder bundle, so you can gather as much sunlight as possible. 

The more direct sunlight you can focus through the lens, the more intense the light will be. 

Rotate the lens from side to side and adjust the distance between the lens and tinder bundle until you focus the light into the smallest beam possible. 

When done correctly, your beam of light will be about a penny's size and will be almost white in color.

Using a steady hand, you should begin to see smoke in just a few seconds.

Even though you see smoke initially, the tinder bundle won't burst into flames. 

Most of the time, you'll just get a small ember to form.

Once you see the ember, gently blow on the ember until it lights the tinder bundle.

Helpful Hints

To light a fire with a fresnel lens use these helpful hits to get the best results:

• Choose a lens with a 4x or 5x magnification
• Use dry tinder
• Attempt this on a sunny day when the suns at it's highest peak
• Keep a steady hand and focus the light into the smallest beam possible
• Be patient, becuase not all tinder will light quickly.

Overall

If you are a lover of the outdoors, you do not need to carry a lighter or a matchbox to start a fire.

The more ways you know of how to light a fire, the better your chances of survival.

Even though you're at the mercy of Mother Nature, a credit card magnifier will work to start a fire.

Magnifying glasses are some of the earliest used tools.

As much as it is an old technique, it remains a great tool to carry in your wallet as it is pretty portable.

There are various types of Fresnel lenses, just be sure to get one that meets or satisfies your needs.

Once you use it several times, you can now get used to its focal length.

Lighting a fire will become quite straightforward.

While you shouldn't rely on it as your primary method of starting a fire, the Fresnel lens' compact and lightweight design, along with its affordability, makes it a welcome addition to any survival kit.

About the Author

Nick Greenway

Obsessed with firewood, Nick is behind over 350+ of Firewood For Life's articles, as well as countless reviews, guides and YouTube videos to help readers like you reduce heating costs and create the perfect fire.