Fresnel Lens Yesterday and Today

With the long, dark winter nights we’re experiencing in the Northern Hemisphere, it is a good time to celebrate the marvel of an invention that brought light to our world centuries ago, and still today.

Even before the first light bulb was invented, a powerful lens was invented.

It was a modern invention of the 1820s that revolutionized the sciences of light and marine navigation.

The lens design, created by a physicist, was maximized to capture light reflection and refraction. It is an array of prisms managing the mechanics of light, extending the light to then-unprecedented lengths.

The inventor, Augustin Fresnel (1788-1827), lived on the rugged west coast of France near Brittany, where tragic shipwrecks repeatedly occurred and human lives frequently perished. He invented the lens for lighthouses, to light up the coast more efficiently for ship captains to see what was in front of them. The first Fresnel lens was installed there, on the coast of France, in 1822.

A Fresnel lens could easily throw its light 20 or more miles.

France, and then Scotland, commissioned the lenses for lighthouses; eventually they spread across the world. The Fresnel lens came to U.S. lighthouses in the 1850s.

Prior to the Fresnel (pronounced fray-NEL) lens invention, oil lamps supplied the light and various inventions helped extend the light, but it was not enough to prevent shipwrecks.

I came upon this discovery not by navigating a ship along the coast, but by hiking on an island in the San Francisco Bay. Angel Island.

In the visitor center, a nearly two-foot glass structure shaped like a beehive was perched on a stand near the door–caught my attention.

I am one of those people who stops in their tracks for shadows and sunbeams, fascinated by reflections and refractions. And this giant piece of glass was winking up a storm at me.

It is 21.3 inches high (.54 m). Fresnel lenses come in different sizes, or orders. Both lenses in this post are 5th Order. 1st Order is the largest, 6th Order is smaller. Link for more info is below.

The original Fresnel lenses can often be seen in lighthouses, like this one at Point Robinson on Vashon Island in Washington. The lamp/lens is inside the lighthouse (below), visible underneath the red, cone-shaped roof.

Here is a closer look at the lens, with majestic Mount Rainier presiding in the background.

Though there are still Fresnel lenses in lighthouses today, the science has largely been replaced by navigational systems like radar and radio signal towers and global positioning systems (GPS).

There are many lighthouses that still have the original Fresnel lenses, most of which are no longer operational. Almost always the lens/lamp is there due to a concerted effort by maritime enthusiasts, volunteers, and donations. Today they are highly regarded and valuable treasures.

The United States Lighthouse Society has a website filled with information about U.S. lighthouses including two lists of lighthouses that have operational and non-operational Fresnel Lenses.

Link: Fresnel Lenses in the U.S.

Link: Operational Fresnel Lenses in the U.S.

Link: Wikipedia Fresnel Lens

Link: Augustin-Jean Fresnel Wikipedia

The magic of the Fresnel lens does not stop in the 1800s. Today working Fresnel lenses are found in spotlights, floodlights, railroad and traffic signals, emergency vehicle lights and more.

Photographers use them to illuminate a scene. Athena uses a Fresnel lens flash extender on her camera, especially when we are out birding on night walks or dark days. It is a flimsy plastic lens that attaches to the flash unit and extends the flash up to 300 feet (91 m).

She captured this scene below with her “Better Beamer” flash extender. We were in the Belizean rainforest when a spectacled owl had just snatched up a fer-de-lance snake and landed in a tree 200 feet away (61 m).

The Fresnel lens has been bringing light into this world for ages, whether it was preventing fatal shipwrecks two centuries ago or capturing dynamic owl scenes today. That is something to celebrate.

Written by Jet Eliot.

Photos by Athena Alexander.


72 thoughts on “Fresnel Lens Yesterday and Today

  1. Most interesting post, Jet! I am fascinated with fresnals too, the lights, reflections and colors they throw. I did not know anything about attaching a Fresnel lens flash extender to a camera, wow! Going to check that out!!

    • I’m happy you enjoyed the Fresnel post today, Donna. You will love the flash extender for your camera, especially being a birder and in less-than-perfect light all the time. They sell them at B&H and other places, not expensive. They’re flimsy and a little hinky, but they work. Many thanks for your visit.

    • I’m delighted you enjoyed the Fresnel post today, Timothy. No lighthouses in NM, yes, makes sense. I’m glad I could share them with you here. Sending you a big smile, Timothy, and thanks.

    • Wonderful that you have seen the Fresnel lens, Cathy. They are rather mysterious looking and whenever I’ve been near one, I seem to be the only person who is absolutely thrilled. You’re right, they are not immediately understandable, especially two centuries later. Many thanks.

  2. Totally interesting story on just how the ‘lighthouse’ evolved. Always believed it had
    to be devolved somehow but just was not such how. Thanks for answering those
    questions for me and then some Jet. A great post, have a wonderful day Jet! Eddie

  3. It’s unfortunate that Fresnel died so young of TB. He accomplished so much. He would of been tickled to see lasers. I wonder how the light would react to a source such as a laser?
    Light is energy transmission. A single photon takes many thousands of years once created to warm our cheek.

    • Yes, tragic that Fresnel died so young, but what a plethora of inventions he left us with in his short time here. I am glad this post got you thinking about the glories of light and lasers, Wayne. Cheers to you.

  4. I love lighthouses and learned about the Fresnel lens while visiting them years ago. I bought a miniature one from Point Cabrillo Lightstation eons ago. I use it as a Christmas ornament so get to see it and watch it play with the light each year while it’s on my tree.

    I have a Better Beamer! I haven’t used it in an age! To be honest I forgot all about it. I’ll have to look for mine. I haven’t seen it since our move. I bought one because I wanted to get shots like that amazing shot Athena got of the owl. I haven’t got a shot with it…yet. 😀

  5. Thanks for this enlightening post about the Fresnel, Jet. I’d known just a bit about its use in lighthouses but not a whole lot more, so I appreciate the technological update. Athena’s capture of the tropical owl with snake is simply stunning.

    • It is great that you were familiar with the Fresnel, and that I could fill you in on some of the details, Walt. Glad you liked the owl and snake photo. It all happened in about 20 seconds, but she was on it. Always a joy, my friend…thank you.

  6. I love it when I learn something new (well … new to me). That Fresnel fellow only lived to be 39 years old. What a shame! Imagine what other wonderful things he might have invented if he’d had a longer life. And to apply it to a camera that enabled Athena to take such a great picture, is an added bonus. Thanks for this enlightening post, Jet.

    • I am happy you enjoyed and learned from the Fresnel post today, Anneli. It is amazing what Fresnel all accomplished in his short life. Thank you for your visit today and kind words.

    • Yes, Athena’s camera has been put to good use and the Fresnel lens, too. She is in the process of switching over to new technology, something lighter, but meanwhile she’s doing well with it. Went to the Pt. Reyes Lighthouse this week and she got some terrific photos. I hope this week went well for you, Jan, as you hobble and heal and get better. Take good care…and thanks for your visit.

  7. I really enjoyed this post, Jet – illuminating! What a fabulous invention, and it’s great to read it still has so many uses today, like with Athena’s Better Beamer (a huge thank you and smile to the commentator calling it a Betty Beamer – wonderful!)
    I hope your weekend to come is full of light!

    • Fun to read your comment, pc, I am smiling. I enjoyed your references to light, and send you my best wishes for a lovely weekend, also full of light. Cheers to Mrs. PC and Scout too.

  8. Dear Jet…I always learn so much from you – This post is superb….thank you my friend.
    I think you know that I spend a lot of time on the coast of Brittany – where lighthouses are so necessary….given the storms that occur in that area. I will now have a greater understanding of the lighthouse workings…thanks to you:) X

    • Thanks, Janet, for this wonderful comment. It is such a thrill to know your Brittany coast experiences will have new understanding with the info from this post. Oh how I would love to visit the Brittany coast. Big smiles and thanks for your visit.

    • Yes, isn’t it wonderful to know a human mind worked this out. Light is so complicated. There are incredible equations involved with this scientifically shaped globe of prisms. And how lucky we are when someone like Fresnel succeeds at bringing their brilliance forward to share in the efforts of peace and goodness. Many thanks, Eliza, for your lovely comment.

    • Hi H.J. Yes, isn’t it wonderful that the problem of frequent shipwrecks got worked out? It was so devastating, these disasters, and they figured out how to resolve it. My warmest thanks to you, dear friend, and a big smile too.

    • Your comment has me chuckling, Diana. You didn’t know you didn’t know…clever words and fun. How wonderful that I could share some new info with you. Thanks very much for stopping by.

  9. I knew about these and think they’re very interesting. Aside from what they do, even the geometric shapes are intriguing. Also, that owl has a very dangerous meal. I had to check the gates prior to sunrise so the roofers could access the yard while I was at work yesterday. A great horned owl hooted at me walking around in the dark with my flashlight. I wasn’t worried about him dropping a fer-de-lance on me from above.

    • You’re exactly right, Craig, the fer-de-lance is powerfully poisonous. Irritable, fast-moving and fiercely venomous. Just as well that it was 200 feet away. I liked hearing about the great-horned owl that greeted you the other day. Glad you enjoyed the Fresnel info, too. I thank you for your lovely words today, and your visits are always a joy.

  10. Cool glass! There’s a double-flash fresnel on Kauai at the lighthouse on the north shore. The tour guides there like to tell a story about a B-29 crew in WW-II that became lost in a storm. Their squadron had been aiming for O’ahu from the mainland. When the navigator saw the double flash he knew they were off course and in trouble. But he was able to plot a course correction and save the crews and planes. Much better when they tell it.

    • I loved hearing about the WWII B-29 that was able to re-direct from the Fresnel on Kauai, Brad. That Kilauea Lighthouse is one of the most beautiful places in the world, I have visited it twice. Excellent birding at Kilauea Point. But this info is new to me…and much appreciated. Thanks very much.

  11. Very welcome. Our tour guide asked where we were from (don’t they always). She and her husband had just moved to Kauai from the same part of Central IL. I suspect we had a much longer story than most get at that point.

  12. What a delightful read.

    These are amazingly descriptive sentences:

    “I am one of those people who stops in their tracks for shadows and sunbeams, fascinated by reflections and refractions. And this giant piece of glass was winking up a storm at me.“

  13. This is a fascinating post Jet. I had no idea about Fresnel lenses or how powerful they were. Thanks for the fun education, and it’s nice to see Athena and her magic camera for more light reflections and refractions. 😊

  14. I’ve always enjoyed the Fresnel lenses I’ve seen, both as art and science. I’m glad you included links to the lists of active/inactive ones. We have no active ones on the Texas coast, but I’ve seen all of our original lenses in museums. I suspect that the nature of the Texas coast led to them being discontinued here. There’s nothing to impede an electronic signal moving from the Texas ports out into the Gulf; I suspect those signals can be picked up farther from the coast than an actual light could be.

    What I didn’t know was that the so-called ‘Kemah Lighthouse’ actually is a lighthouse: sort of. The thing stands inland along a busy highway not far from me; it’s also a water tower. I’ve never seen the thing lighted since it was built, and always assumed it was meant as decoration. I looked up its history, and learned that the lens in it is a replica made of acrylic; it’s not glass. I’m going to have to keep an eye on it and see if it ever is lighted up, since it’s on my way to my favorite grocery store!

    • Gosh, Linda, this was astounding. Thank you for this info and the link to the Kemah Lighthouse. How exciting for you to have learned this info about your community tower. I also went to the Artworks Florida website and was pleasantly transfixed by their videos demonstrating their incredible restoration work on Fresnel lenses. Absolutely incredible! Many thanks.

  15. Enjoyed your writeup. Its almost magic the way it reflects light so as to see the light so far away. My boating sometimes takes me to the ocean and I never lose site of land and never go in the dark and I do trust the GPS, but it is comforting to have a physical sighting of the buoy or lighthouse to show me the way.

    • I so enjoyed hearing about your experiences with boating and the lighthouse that lights your way, Bill. I really appreciated hearing it from your mariner’s angle, thank you.

  16. I was wondering if she had the Better Beamer and sure enough you answered that almost immediately. I am always amazed at how the mind of one person can have such and impact on the current times.. much more when those concepts live on so many years later. Thank you for the fascinating look back at what is probably now a nearly forgotten time.

    • I really enjoyed your thoughtful comment, Brian, thank you. I, too, am amazed at how one person’s ideas and actions can still be helping us centuries later. Cheers to you, and thanks.

  17. You just en”lightened” me about the lights that saved many a life on the sea in lighthouses. I’ve seen a few but was unaware of the history involved so thank you for teaching me something new today. I saw that Massachusetts has several existing fresnels but was surprised to see none listed for Maine where there are quite a few along the coast.
    I was aware of the Better Beamer although I have never used one as I am not a bird photographer to any serious extent. Reading about how a fresnel can throw light such distances the value of the Beamer is apparent.

    • It’s wonderful that you knew about the Better Beamers, Steve, and that there were a few new things you learned from the Fresnel post. I’m glad, too, that you had an extra moment to look at the list of the existing lenses. My warm thanks for your visit.

    • I am delighted you found the Fresnel lens post interesting, Nan. And I agree that it’s a marvel they are still being used today. Always a joy to have you visit, thank you.

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