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Here: (pronounced ['frɛz.nəl] or [freɪ'nɛl]) In the Fresnel bio article:(French pronunciation: [ɔgystɛ̃ ʒɑ̃ fʁɛnɛl]; pronounced /freɪˈnɛl/ fray-NELL in English) Why would we pronounce the two uses differently? (As far as I know, saying a "z" in the word is bad usage) Hoemaco ( talk) 17:35, 19 October 2008 (UTC)
The four references are all password protected. Would not it be better to use passwords that are not protected? KudzuVine 21:42, 27 May 2007 (UTC)
Just a quick word. This whole page is talking about compressed optical lenses. I'm pretty sure that these are not Fresnel Lenses. The ones mentioned here are mistakenly called Freznel lenses because they are essentially flat like a Fresnel Lens. [[zone plate|Fresnel zone plates}} are the actual Fresnel Lenses. -- WB-Frontier 11:12, 10 April 2006 (UTC)
What's the highest resolution for one? lysdexia 11:50, 22 Oct 2004 (UTC)
These aren't that great. And wouldn't be used anywhere were resolution is important. But they work quite well for things like overhead projectors. -- WB-Frontier 11:12, 10 April 2006 (UTC)
Canon makes two lenses that use Diffractive Optics, the EF 400mm f/4 DO IS USM and the EF 70-300mm f/4.5-5.6 DO IS USM http://www.canon.com/camera-museum/tech/report/200106/report.html http://www.canon.com.au/products/cameras_lenses_accessories/super_telephoto_lenses/ef400mmf4isusm.html http://www.canon.com.au/products/cameras_lenses_accessories/telephoto_zoom_lenses/ef70-300mmf4.5-5.6doidusm.html http://www.the-digital-picture.com/Reviews/Canon-EF-400mm-f-4.0-DO-IS-USM-Lens-Review.aspx http://www.luminous-landscape.com/reviews/lenses/400-do.shtml http://www.dpreview.com/news/0009/00090604canon_400do.asp
I was surprised by
this engineering prof claiming Fresnel had nothing to do with it.
This page implies
David Brewster claimed the honor.
AZ State Engineering and (according to the snippet in the Google search)
Encyclopædia Britannica, credit
Buffon.
(As does
Beavertail Lighthouse Museum, which I found interesting because lighthouse fans seem prone to putting up silly "parrot the answer I want to hear" quizzes.
[1]
[2]
[3]
[4]
[5])
Fresneltech (pg 2) claims that the famous
Condorcet was in on it besides Buffon and Brewster. My read is that the crucial idea of the segmented lens was not Fresnel's, not even as an independent reïnvention; his contribution seems to have been flattening.
Kwantus 18:50, 2005 Jan 27 (UTC)
My recent change also added a little more on the prismatic elements found in lighthouse Fresnels. This might want to move out of the "Uses" section, and could use a diagram of the light paths.
If there's standard terminology to describe the planar Fresnel (made by flattening a planoconvex lens) we usually think of versus the full-on constellation including these catadioptric elements, I don't know it.
Eub 07:21, 28 September 2005 (UTC)
Removing text "A related optical device is the Fresnel zone plate." because I don't see how they're related, beyond the inventor's name. If you do, please re-add this text with explanation. Eub 05:40, 29 September 2005 (UTC)
The traffic light article states that some new lights use Fresnel lenses to limit the visibility of the light to cars in specific lanes. While I have seen such sytems in some intersections, I don't know enough about the subject to definitively link traffic lights and Fresnel lenses. Could someone more knowledegable than I add a section on this form of implementation, if these lenses are in fact used in traffic lights? — EagleOne\ Talk 18:02, 28 April 2006 (UTC)
Would be great if someone could create a diagram showing the path of the light rays.
Would love to see an explanation of the differences between first, second, third, and fourth order Fresnel lenses referenced but not explained in this article. There is a photo of a third order lense and a notation in other locations about the detroit river light house having donated it's fourth oder fresnel lense to a museum and I now wonder just what the differences might be between these types. If anyone can shed some light (pun intended) it would be most appreciated. —Preceding unsigned comment added by 151.166.15.114 ( talk) 19:19, 6 July 2010 (UTC)
Lighting gaffers use the focusing ability of Fresnel instruments for two purposes: to modify light intensity by spreading or narrowing the beam and to change beam-edge characteristics (from hard to soft). Beam edges are masked by one or both of two methods: by "barn door" flaps mounted on hinges in front of the lens and moved in and out of the light path, and/or by "flags:" (usually) rectangular sheets or paddles placed on separate stands some distance in front of the lighting instrument. Both masking techniques can be fine-tuned by altering the focus of the light beam. A hard line edge may be wanted or a fairly subtle falling off -- or anything in between.
Not sure any of this properly belongs in the Fresnel article though. -- Jim Stinson 00:11, 11 July 2007 (UTC)
I touched up the paragraph on theater and motion pictures slightly to improve accuracy (the phrase I cut: "brighter than a typical lens" is too vague. What is a typical lens? Jim Stinson 02:53, 23 October 2007 (UTC)
Development
The idea of creating a thinner, lighter lens by making it with separate sections mounted in a frame is often attributed to Georges-Louis Leclerc, Comte de Buffon.[1] However, it is difficult to find any other sources that link Buffon to work with optics. French physicist and engineer Augustin-Jean Fresnel is most often given credit for the development of this lens for use in lighthouses. According to Smithsonian, the first Fresnel lens was used in 1822 in a lighthouse on the Gironde River in France, Cardovan Tower; its light could be seen from more than 20 miles out.[2] Scottish physicist Sir David Brewster is credited with convincing the British to use these lenses in their lighthouses.[3][4]
More specificaly. what does this mean???
is often attributed to Georges-Louis Leclerc, Comte de Buffon.[1] However, it is difficult to find any other sources that link Buffon to work with
Any other sources??, other than what?? Georges-Louis is the subject, I can understand that. What are these previously unmentioned other sources?? Wouldn't it be better to just leave them out altogether!
Oh, and while I am at it, isn't it, "the Smithsonian Institute", or something like that, somone needs to look at a style guide!!!!! —Preceding unsigned comment added by 124.182.67.203 ( talk) 04:51, 23 November 2007 (UTC)
One of the paragraphs in the 'Uses' section contains a redlink to 'retina identification'. I thought I might point it to retinal scan, possibly retaining the original wording - does anyone who knows more than I about the subject know of any reason why that might be a bad or misleading idea? Cooperised ( talk) 21:17, 2 April 2008 (UTC)
Diffractive telescopes with Fresnel lenses fabricated on thin membranes offer several advantages over telescopes that use mirrors: thin-membrane lenses are lightweight, packageable, and space-deployable. Transmissive diffractive lenses are significantly less sensitive to surface deformations than mirrors, and the chromatic effects of the diffractive primary can be completely compensated for. As a first step in developing the Eyeglass technology, LLNL scientists built and tested a small-aperture (20-cm), color-corrected diffractive telescope and obtained a broadband image of the lunar surface. Next, they built and demonstrated an 80-cm-aperture segmented, foldable lens. In 2002, the researchers constructed a 5-m, f/50 Fresnel lens – comprising 72 segments patterned with binary Fresnel arcs in photoresist – and secured it to a 750-μm-thick sheet of glass with UV-curable cement and metal tabs. The assembled lens was mounted in a frame and the focal spot of a white-light source mounted at the opposite focus was imaged. This demonstration lens was not made to give diffraction-limited performance, but to demonstrate assembly and deployment at a scale large enough to be of interest for imaging. The surfacetension gradient between a thin film adhering to a substrate and a free surface of falling film is strong enough to pull etchant off of the substrate surface. Regardless of substrate movement, the wetted zone remains stationary relative to the applicator. The Marangoni effect can also be thermally driven.
https://lasers.llnl.gov/programs/psa/pdfs/technologies/eyeglass_space_telescope.pdf
217.196.160.253 ( talk) 00:18, 7 April 2008 (UTC) 217.196.160.253 ( talk) 00:21, 7 April 2008 (UTC) 217.196.160.253 ( talk) 00:23, 7 April 2008 (UTC)
Here is a recent news article on attempt to detect life in distant star systems using a Fresnel lens (Economist, June 9, 2012, "The Search for Alien Life: Twinkle, Twinkle, Little Planet"): http://www.economist.com/node/21556552, Catrachos ( talk) 14:04, 14 June 2012 (UTC)
The references do not seem to support the contention that the order of a lighthouse lens is roughly equal to its power in diopters. The correspondence is extremely rough, and only works for the American ranking, not Fresnel's original system (at least as given in the referenced chart from the LoC). This claim needs a definite citation of its own. Mangoe ( talk) 14:34, 4 October 2008 (UTC)
Fresnel reflector is currently redirecting here. I don't believe Fresnel reflectors are a type of Fresnel lens so I plan to move the information on Fresnel reflectors to their own article. It will have links back here. Lumenos ( talk) 21:28, 10 June 2009 (UTC)
I was surprised to see what looks to my untutored eye to be a Fresnel lens in a Renaissance painting of Caravaggio, The Taking of Christ.
The unhelmeted soldier on the right raises a lantern that holds the lens. We can see the characteristic light through the lens (or rather what I'm guessing that light might look like) in two bands on the billowing cloak of the terrified St. John, who's running away screaming.
Would you characterize as a crude "Fresnel" lens this lantern glass from the early seventeenth century? It might be worth mentioning in the article if so. Pete142 ( talk) 22:58, 14 October 2010 (UTC) Pete Wilson
In the description, it says " <<<Actually 'single-piece' Fresnel lenses have been produced for decades. Such examples are Also, brake, parking, and turn signal lenses, all being of one piece of glass, also use this technology, and have been produced for years without the aid of computers." This is confusing and almost contradictory. Perhaps it should say; "It was not until modern computer-controlled milling equipment (CNC) could turn out large complex pieces that these lenses were manufactured from single pieces of glass. However, smaller fresnel lenses have been widely produced for decades without the aid of computers. Some examples include automobile headlamps, with their multi-faceted lenses that direct the light into a particular pattern and direction."
http://lighthouse-society.org/assets/resources/articles/fresnel_lens_1.pdf
Are the lenses cast as one or individual prisms?-- Ericg33 ( talk) 08:29, 30 June 2011 (UTC)
I would first apologize for the intemperate and uncalled for use of the word "idiot." Indeed, I think the gallery needs to be cleaned up, as it does partially look like a random collection of photos. But "clean up" does not mean "eliminate". I don't think that the person who put the template on ever meant for it to be so interpreted. 7&6=thirteen ( ☎) 19:47, 8 September 2012 (UTC)
I believe that in the picture, the lens disperses the light, it does not focus it. _ Mr.Shoval ( talk) 22:07, 8 June 2013 (UTC)
Why is there a link to "Random Destructive Acts via Focused Solar Radiation"? It's a personal website about people who destroyed things with a Fresnel lens. Is there anything of interest for the article? Does it bear a relation with any part of the article? Jelt ( talk) 21:08, 16 September 2013 (UTC)
I reversed today's edits. A diffractive optical element is not a Fresnel lens. Both types of optical element can have a flat overall profile and obtain focusing by grooves in the surface, but the mechanism is different. A Fresnel lens focuses light by simple refraction: the lens surface is broken up into small regions, each of which refracts light in the correct direction to form a focus. A diffractive optical element, on the other hand has grooves in its surface that are closer together than the wavelength of light. These closely-spaced grooves redirect light rays by diffraction rather than refraction.
Adding to the confusion between the two types of lens, Fresnel did a lot of work on diffraction, and his analyses led to the development of some of the first diffractive optics, such as Fresnel zone plates.-- Srleffler ( talk) 02:32, 14 October 2013 (UTC)
Mention if Fresnel lenses have been found in nature. Jidanni ( talk) 02:59, 17 April 2014 (UTC)
Mention if looking through Fresnel lenses are worse for the eyes than conventional lenses. Jidanni ( talk) 02:59, 17 April 2014 (UTC)
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The photo that has the caption "first order Fresnel lens on the left" shows three more lenses. It would be good to say what order those lenses are. Bubba73 You talkin' to me? 19:22, 14 March 2016 (UTC)
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What about concave Fresnel lens?-- وسام زقوت ( talk) 14:54, 15 February 2017 (UTC)
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These are used in neurology
Frenzel lens can be used in provocation study to help diagnose the cause of vertigo. The frenzel lens is used to keep a patient’s vision blurry while the physician can easily see the payient’s Eyes.
In the provocation study, the patients head is shaken to determine if vertigo or nystagmus occur, and in which direction the nystagmus occurs.
I believe ophthalmology uses frenzel lenses as well. Tmbirkhead ( talk) 19:17, 23 October 2018 (UTC)
Fresnel lens have been in use in VR (Virtual Reality) headsets since 2016. I'm surprised they are not mentioned in this article at all. The Vive has them, for instance. Lolsocks ( talk) 01:40, 31 December 2019 (UTC)
Search lights, spot lights, and flashlights.
Drsruli ( talk) 07:28, 2 March 2022 (UTC)
your article claims there is only 3 1st order fresnel lenses (largest) left and they are in New England, that is wrong..... Haceta Head Lighthouse in Southern Oregon has one of the 1st order I know because I just went on the tour. It is still in use! 166.181.250.9 ( talk) 11:30, 7 January 2024 (UTC)
![]() | This ![]() It is of interest to the following WikiProjects: | |||||||||||||||||||||||||||
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Here: (pronounced ['frɛz.nəl] or [freɪ'nɛl]) In the Fresnel bio article:(French pronunciation: [ɔgystɛ̃ ʒɑ̃ fʁɛnɛl]; pronounced /freɪˈnɛl/ fray-NELL in English) Why would we pronounce the two uses differently? (As far as I know, saying a "z" in the word is bad usage) Hoemaco ( talk) 17:35, 19 October 2008 (UTC)
The four references are all password protected. Would not it be better to use passwords that are not protected? KudzuVine 21:42, 27 May 2007 (UTC)
Just a quick word. This whole page is talking about compressed optical lenses. I'm pretty sure that these are not Fresnel Lenses. The ones mentioned here are mistakenly called Freznel lenses because they are essentially flat like a Fresnel Lens. [[zone plate|Fresnel zone plates}} are the actual Fresnel Lenses. -- WB-Frontier 11:12, 10 April 2006 (UTC)
What's the highest resolution for one? lysdexia 11:50, 22 Oct 2004 (UTC)
These aren't that great. And wouldn't be used anywhere were resolution is important. But they work quite well for things like overhead projectors. -- WB-Frontier 11:12, 10 April 2006 (UTC)
Canon makes two lenses that use Diffractive Optics, the EF 400mm f/4 DO IS USM and the EF 70-300mm f/4.5-5.6 DO IS USM http://www.canon.com/camera-museum/tech/report/200106/report.html http://www.canon.com.au/products/cameras_lenses_accessories/super_telephoto_lenses/ef400mmf4isusm.html http://www.canon.com.au/products/cameras_lenses_accessories/telephoto_zoom_lenses/ef70-300mmf4.5-5.6doidusm.html http://www.the-digital-picture.com/Reviews/Canon-EF-400mm-f-4.0-DO-IS-USM-Lens-Review.aspx http://www.luminous-landscape.com/reviews/lenses/400-do.shtml http://www.dpreview.com/news/0009/00090604canon_400do.asp
I was surprised by
this engineering prof claiming Fresnel had nothing to do with it.
This page implies
David Brewster claimed the honor.
AZ State Engineering and (according to the snippet in the Google search)
Encyclopædia Britannica, credit
Buffon.
(As does
Beavertail Lighthouse Museum, which I found interesting because lighthouse fans seem prone to putting up silly "parrot the answer I want to hear" quizzes.
[1]
[2]
[3]
[4]
[5])
Fresneltech (pg 2) claims that the famous
Condorcet was in on it besides Buffon and Brewster. My read is that the crucial idea of the segmented lens was not Fresnel's, not even as an independent reïnvention; his contribution seems to have been flattening.
Kwantus 18:50, 2005 Jan 27 (UTC)
My recent change also added a little more on the prismatic elements found in lighthouse Fresnels. This might want to move out of the "Uses" section, and could use a diagram of the light paths.
If there's standard terminology to describe the planar Fresnel (made by flattening a planoconvex lens) we usually think of versus the full-on constellation including these catadioptric elements, I don't know it.
Eub 07:21, 28 September 2005 (UTC)
Removing text "A related optical device is the Fresnel zone plate." because I don't see how they're related, beyond the inventor's name. If you do, please re-add this text with explanation. Eub 05:40, 29 September 2005 (UTC)
The traffic light article states that some new lights use Fresnel lenses to limit the visibility of the light to cars in specific lanes. While I have seen such sytems in some intersections, I don't know enough about the subject to definitively link traffic lights and Fresnel lenses. Could someone more knowledegable than I add a section on this form of implementation, if these lenses are in fact used in traffic lights? — EagleOne\ Talk 18:02, 28 April 2006 (UTC)
Would be great if someone could create a diagram showing the path of the light rays.
Would love to see an explanation of the differences between first, second, third, and fourth order Fresnel lenses referenced but not explained in this article. There is a photo of a third order lense and a notation in other locations about the detroit river light house having donated it's fourth oder fresnel lense to a museum and I now wonder just what the differences might be between these types. If anyone can shed some light (pun intended) it would be most appreciated. —Preceding unsigned comment added by 151.166.15.114 ( talk) 19:19, 6 July 2010 (UTC)
Lighting gaffers use the focusing ability of Fresnel instruments for two purposes: to modify light intensity by spreading or narrowing the beam and to change beam-edge characteristics (from hard to soft). Beam edges are masked by one or both of two methods: by "barn door" flaps mounted on hinges in front of the lens and moved in and out of the light path, and/or by "flags:" (usually) rectangular sheets or paddles placed on separate stands some distance in front of the lighting instrument. Both masking techniques can be fine-tuned by altering the focus of the light beam. A hard line edge may be wanted or a fairly subtle falling off -- or anything in between.
Not sure any of this properly belongs in the Fresnel article though. -- Jim Stinson 00:11, 11 July 2007 (UTC)
I touched up the paragraph on theater and motion pictures slightly to improve accuracy (the phrase I cut: "brighter than a typical lens" is too vague. What is a typical lens? Jim Stinson 02:53, 23 October 2007 (UTC)
Development
The idea of creating a thinner, lighter lens by making it with separate sections mounted in a frame is often attributed to Georges-Louis Leclerc, Comte de Buffon.[1] However, it is difficult to find any other sources that link Buffon to work with optics. French physicist and engineer Augustin-Jean Fresnel is most often given credit for the development of this lens for use in lighthouses. According to Smithsonian, the first Fresnel lens was used in 1822 in a lighthouse on the Gironde River in France, Cardovan Tower; its light could be seen from more than 20 miles out.[2] Scottish physicist Sir David Brewster is credited with convincing the British to use these lenses in their lighthouses.[3][4]
More specificaly. what does this mean???
is often attributed to Georges-Louis Leclerc, Comte de Buffon.[1] However, it is difficult to find any other sources that link Buffon to work with
Any other sources??, other than what?? Georges-Louis is the subject, I can understand that. What are these previously unmentioned other sources?? Wouldn't it be better to just leave them out altogether!
Oh, and while I am at it, isn't it, "the Smithsonian Institute", or something like that, somone needs to look at a style guide!!!!! —Preceding unsigned comment added by 124.182.67.203 ( talk) 04:51, 23 November 2007 (UTC)
One of the paragraphs in the 'Uses' section contains a redlink to 'retina identification'. I thought I might point it to retinal scan, possibly retaining the original wording - does anyone who knows more than I about the subject know of any reason why that might be a bad or misleading idea? Cooperised ( talk) 21:17, 2 April 2008 (UTC)
Diffractive telescopes with Fresnel lenses fabricated on thin membranes offer several advantages over telescopes that use mirrors: thin-membrane lenses are lightweight, packageable, and space-deployable. Transmissive diffractive lenses are significantly less sensitive to surface deformations than mirrors, and the chromatic effects of the diffractive primary can be completely compensated for. As a first step in developing the Eyeglass technology, LLNL scientists built and tested a small-aperture (20-cm), color-corrected diffractive telescope and obtained a broadband image of the lunar surface. Next, they built and demonstrated an 80-cm-aperture segmented, foldable lens. In 2002, the researchers constructed a 5-m, f/50 Fresnel lens – comprising 72 segments patterned with binary Fresnel arcs in photoresist – and secured it to a 750-μm-thick sheet of glass with UV-curable cement and metal tabs. The assembled lens was mounted in a frame and the focal spot of a white-light source mounted at the opposite focus was imaged. This demonstration lens was not made to give diffraction-limited performance, but to demonstrate assembly and deployment at a scale large enough to be of interest for imaging. The surfacetension gradient between a thin film adhering to a substrate and a free surface of falling film is strong enough to pull etchant off of the substrate surface. Regardless of substrate movement, the wetted zone remains stationary relative to the applicator. The Marangoni effect can also be thermally driven.
https://lasers.llnl.gov/programs/psa/pdfs/technologies/eyeglass_space_telescope.pdf
217.196.160.253 ( talk) 00:18, 7 April 2008 (UTC) 217.196.160.253 ( talk) 00:21, 7 April 2008 (UTC) 217.196.160.253 ( talk) 00:23, 7 April 2008 (UTC)
Here is a recent news article on attempt to detect life in distant star systems using a Fresnel lens (Economist, June 9, 2012, "The Search for Alien Life: Twinkle, Twinkle, Little Planet"): http://www.economist.com/node/21556552, Catrachos ( talk) 14:04, 14 June 2012 (UTC)
The references do not seem to support the contention that the order of a lighthouse lens is roughly equal to its power in diopters. The correspondence is extremely rough, and only works for the American ranking, not Fresnel's original system (at least as given in the referenced chart from the LoC). This claim needs a definite citation of its own. Mangoe ( talk) 14:34, 4 October 2008 (UTC)
Fresnel reflector is currently redirecting here. I don't believe Fresnel reflectors are a type of Fresnel lens so I plan to move the information on Fresnel reflectors to their own article. It will have links back here. Lumenos ( talk) 21:28, 10 June 2009 (UTC)
I was surprised to see what looks to my untutored eye to be a Fresnel lens in a Renaissance painting of Caravaggio, The Taking of Christ.
The unhelmeted soldier on the right raises a lantern that holds the lens. We can see the characteristic light through the lens (or rather what I'm guessing that light might look like) in two bands on the billowing cloak of the terrified St. John, who's running away screaming.
Would you characterize as a crude "Fresnel" lens this lantern glass from the early seventeenth century? It might be worth mentioning in the article if so. Pete142 ( talk) 22:58, 14 October 2010 (UTC) Pete Wilson
In the description, it says " <<<Actually 'single-piece' Fresnel lenses have been produced for decades. Such examples are Also, brake, parking, and turn signal lenses, all being of one piece of glass, also use this technology, and have been produced for years without the aid of computers." This is confusing and almost contradictory. Perhaps it should say; "It was not until modern computer-controlled milling equipment (CNC) could turn out large complex pieces that these lenses were manufactured from single pieces of glass. However, smaller fresnel lenses have been widely produced for decades without the aid of computers. Some examples include automobile headlamps, with their multi-faceted lenses that direct the light into a particular pattern and direction."
http://lighthouse-society.org/assets/resources/articles/fresnel_lens_1.pdf
Are the lenses cast as one or individual prisms?-- Ericg33 ( talk) 08:29, 30 June 2011 (UTC)
I would first apologize for the intemperate and uncalled for use of the word "idiot." Indeed, I think the gallery needs to be cleaned up, as it does partially look like a random collection of photos. But "clean up" does not mean "eliminate". I don't think that the person who put the template on ever meant for it to be so interpreted. 7&6=thirteen ( ☎) 19:47, 8 September 2012 (UTC)
I believe that in the picture, the lens disperses the light, it does not focus it. _ Mr.Shoval ( talk) 22:07, 8 June 2013 (UTC)
Why is there a link to "Random Destructive Acts via Focused Solar Radiation"? It's a personal website about people who destroyed things with a Fresnel lens. Is there anything of interest for the article? Does it bear a relation with any part of the article? Jelt ( talk) 21:08, 16 September 2013 (UTC)
I reversed today's edits. A diffractive optical element is not a Fresnel lens. Both types of optical element can have a flat overall profile and obtain focusing by grooves in the surface, but the mechanism is different. A Fresnel lens focuses light by simple refraction: the lens surface is broken up into small regions, each of which refracts light in the correct direction to form a focus. A diffractive optical element, on the other hand has grooves in its surface that are closer together than the wavelength of light. These closely-spaced grooves redirect light rays by diffraction rather than refraction.
Adding to the confusion between the two types of lens, Fresnel did a lot of work on diffraction, and his analyses led to the development of some of the first diffractive optics, such as Fresnel zone plates.-- Srleffler ( talk) 02:32, 14 October 2013 (UTC)
Mention if Fresnel lenses have been found in nature. Jidanni ( talk) 02:59, 17 April 2014 (UTC)
Mention if looking through Fresnel lenses are worse for the eyes than conventional lenses. Jidanni ( talk) 02:59, 17 April 2014 (UTC)
Hello fellow Wikipedians,
I have just added archive links to one external link on
Fresnel lens. Please take a moment to review
my edit. If necessary, add {{
cbignore}}
after the link to keep me from modifying it. Alternatively, you can add {{
nobots|deny=InternetArchiveBot}}
to keep me off the page altogether. I made the following changes:
When you have finished reviewing my changes, please set the checked parameter below to true to let others know.
An editor has reviewed this edit and fixed any errors that were found.
Cheers.— cyberbot II Talk to my owner:Online 19:20, 27 February 2016 (UTC)
The photo that has the caption "first order Fresnel lens on the left" shows three more lenses. It would be good to say what order those lenses are. Bubba73 You talkin' to me? 19:22, 14 March 2016 (UTC)
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What about concave Fresnel lens?-- وسام زقوت ( talk) 14:54, 15 February 2017 (UTC)
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These are used in neurology
Frenzel lens can be used in provocation study to help diagnose the cause of vertigo. The frenzel lens is used to keep a patient’s vision blurry while the physician can easily see the payient’s Eyes.
In the provocation study, the patients head is shaken to determine if vertigo or nystagmus occur, and in which direction the nystagmus occurs.
I believe ophthalmology uses frenzel lenses as well. Tmbirkhead ( talk) 19:17, 23 October 2018 (UTC)
Fresnel lens have been in use in VR (Virtual Reality) headsets since 2016. I'm surprised they are not mentioned in this article at all. The Vive has them, for instance. Lolsocks ( talk) 01:40, 31 December 2019 (UTC)
Search lights, spot lights, and flashlights.
Drsruli ( talk) 07:28, 2 March 2022 (UTC)
your article claims there is only 3 1st order fresnel lenses (largest) left and they are in New England, that is wrong..... Haceta Head Lighthouse in Southern Oregon has one of the 1st order I know because I just went on the tour. It is still in use! 166.181.250.9 ( talk) 11:30, 7 January 2024 (UTC)