How a Lens creates an Image.

Contents:
0:00 Introducing "rays"
2:14 Light is a wave
4:00 Nils reached one thousand!
4:43 Effect of Numerical Aperture
6:46 About "Critical Dimension"
7:40 Effect of NA illustrated using a microscope
10:44 Diffraction in the Double Slit Experiment
12:30 Diffraction in the Circular Slits (Fresnel Zone Plates)
14:40 Effect of central obstruction on focus
15:05 Using diffraction to create an Image
18:59 Comparison to the Fourier Series Approximation
19:44 Image Creation and JPEG compression
20:59 Effect of wavelength on definition
21:35 Extroduction
A list of links to subjects mentioned in the video:
Nils Berglund's Channel: / nilsberglund
Link to the full "NA" video by Nils: • Numerical aperture of ...
Making Fresnel Zone plates: • Making Tiny Fresnel Le...
Building a Maskless Wafer Stepper: • Maskless Wafer Stepper...
Some images were taken from JW Middelink Systematische Natuurkunde Deel B.
This book series is absolutely awesome. They made me enjoy my high school physics classes and that is why I held on to them for 40 years.
The video contains a short audio clip that is inspired on "another one bites the dust" by Queen. I did not use the original drums and bass but, Freddy himself did contribute in his own special way. I consider this fair use but if you are the copyright owner, please contact me in case you consider this a copyright breach. Today on the date of video publication it is 32 years ago exactly that Freddy Mercury died of Aids.
Apparently, the lady in the compression images is named Lena. If I had known the history behind the image and why it became so famous, I would probably not have used it:
pursuit.unimelb.edu.au/articl...
A correction about the name of ASML: currently, this is the actual name of the company, so without any reference to the origin of the abbreviation. Advanced Semiconductor Materials Lithography was the name of the joint venture of ASM (founded by Arthur del Prado) and Philips Electronics, intended for the development of photolithography machines.
Did I forget to mention you? Please contact me and I will sort it out.

[@primenumberbuster404]

The fact that this is the only dedicated optics channel on entire youtube is crazy.

[@davemorphling7432]

I think you're severely underestimating the knowledge, effort, and money required to produce these videos. The fact that there is a single channel with this caliber is a blessing.

[@primenumberbuster404]

@@davemorphling7432 There exists more expensive videos of amateur rocketeers in youtube. Which is infact so much more complicated but yet we have so much of that content on youtube. But for Optics in general with this level of dedication there is hardly any.

[@tokiWren]

@@primenumberbuster404 i would guess this is because there is more information regarding the mechanics of rocketry in circulation. and optics is a much less "exciting" field, somewhat like the idea of "charismatic species" in conservation

[@-r-495]

absolutely!

[@nikoy4266]

Where he said he bought something is eBay and you find out that a semiconductor magnifier checker for nanometer level😂

[@Devorse]

English is not my native language, but I studied it at school. And in addition to the excellent educational part of the video, I would like to note the clear speech of the author, understandable to non-native speakers

[@rschroev]

Interesting because the author is also not a native English speaker (he's Dutch). Maybe that helps non-native speakers to understand his English better.

[@mrtoastyman07]

Peak youtube right here. Everyone take note - this is how you do educational content. So awesome. You and microcosmos inspired me to get a microscope and I've been teaching my daugter about optics - truely thank you for your hard work on these videos!

[@HuygensOptics]

The microscope is totally underrated as an instrument for physics education. Glad you use it. I'm also amazed by the scary looking monsters that are in my pond!

[@trumanhw]

@@HuygensOptics Have you ever checked out the YT channel Lemino ..? It's not physics, but it's perhaps my favorite obscure channel (not that obscure tho).

[@jhgrc]

@@HuygensOptics 3Blue1Brown channel also had interesting video about Prism, explaining what happens inside lens medium, why light slows down with wave propagation.

[@BreakingTaps]

Very, very cool demonstration! Something about seeing a physical demonstration of these principles really makes it clear, compared to simply looking at textbook illustrations. Can't wait for the ASML video too!

[@HuygensOptics]

Thanks Zach! Regarding the visit: what they do at ASML is completely insane, like the synchronized acceleration at 30G with sub-nanometer precision and making accurate projection of billions of device patterns in one go with the same precision routinely possible. I was completely blown away by all the things I was not even aware of were possible...

[@BreakingTaps]

@@HuygensOptics Wow, that's just so completely impossible sounding! What an amazing engineering accomplishment. Can't wait to watch!

[@Luis-qe8el]

Just amazing knowledge and caring, simplicity and detail that Huygens propagates to the world, totally love the idea of ASML sharing too, even if its just the optical part that they use a water plate i think, ty ty for the great content!!

[@GeoffryGifari]

Seeing that Nils Berglund's channel is credited, it strikes me just how connected the KZbin science community is. I could talk to a physics enthusiast halfway across the world and just happened to recognize the same channels

[@giovane_Diaz]

there is even a folk that did a graph analysis of his own audience and got some evidence of just how interconnected this community can be. (and how it is just a tiny table on the huge yt mall world)

[@GeoffryGifari]

@@giovane_Diaz really? do you have the link?

[@idontwantahandlethough]

@@giovane_Diaz I'm not sure I've ever heard someone refer to a singular "folk" before 😂

[@douginorlando6260]

This channel had used Nils Berglund’s animation to depict how multiple sources eventually become solid angle regions of coherent light. This explained a contradiction that puzzled me since the last century … why multiple sources at a particular wavelength bunched together physically do not all cancel each other out due to adding increasing numbers of phase shifted waves? (The randomness of phase shifts implied as number of sources increased, then every wave would have another wave approaching 180 degrees out of phase and thus cancel out). This really messed up the idea of inverse square intensity because at a distance, a light source like a star would have cancelled out all its’ photons and radiated energy would vanish! Nils demonstrated why the waves do cancel in some directions but combine in other directions so like the song in Titanic movie, the radiated energy still goes on. The total energy passing through a Gaussian shell of any radius around the star will remain constant regardless of radius

[@jorymil]

Astronomical sources are so far away from us that they essentially behave as coherent light sources due to their small solid angle. Same reason you put a slit in front of a spectrometer: you're trying to select only in-phase light.

[@user-fq7ow7yj3j]

This video is an absolute gem. You completely delivered on the promise: "if you stick around, you will not disappointed." The reminder that 'these are not simulations, they are real images collected using a microscope' was a kick in the brain. And it's not often I get to have a thought like, "Hmmm. Removing those rings decreases the information like a compression algorithm" and hear only a few minutes later, "The image looks a bit like a heavily compress JPEG image." BRAVO!

[@babysnaykes]

This is a real gem, thankyou for all your work

[@dittilio]

The first few minutes really solidified some things I knew, but kept in different baskets in my brain. I used to design acoustic sensing experiments that used fibre optics strain variation (DAR), and the lensing effects of different materials as sound propagated through soil/gravel/concrete/air etc had dramatic effects on triangulating the source of the sound (small digger near a cable vs. big digger far away). Thanks so much for putting this video together, along with all the others you do.

[@InfraredVisuals]

Awesome! The way you demonstrate the subjects in such detail is invaluable. As always, thank you for making another video. Also, congrats to Nils for making the scientific simulation.

[@computer_in_a_cave2730]

I think I just saw a fiber optic simulation by Nils - amazing - only 80 lines code _ish run on GPUs / you know the graphics card peeps. Multi modal fiber - Does Loki know about this ... hehe.

[@commander-tomalak]

Man, I have never seen anyone explain the creation of an image with a lens from a pure wave perspective, and so clearly at that. I am a working professional in integrated photonics and have a PhD in physics, and I have learned quite a bit today. Thanks!

[@aether5213]

I wonder how many physics PhDs are here in the comments!

[@DanielHeineck]

I did my coursework for my Ph.D in photonics, and your descriptions are fantastic and would have helped me a ton back then. Wonderful work! I would love to see your demonstration of how darkfield illumination/microscopy works, as, selfishly, I'd love to link the video to my coworkers :)

[@jorymil]

Absolutely! There was a picture of Kohler illumination here that made _so_ much sense!

[@nicolascloutier3199]

This second half of the video is the most practical introduction to quantum mechanics I have seen.

[@dsllvv]

This is simply the best explanation I've ever seen. I loved the fact that you showed real experiments. Thank you!

[@alexanderray77]

My father Sidney Ray wrote a number of books on optics. Your videos bring back many memories of those books and of lectures doing my Photographic and Electronic Imaging Science degree. Thank you for this wonderful channel.

[@YSoreil]

Throughout the video I was constantly thinking "Where did I hear high NA before?" and I am so happy to see the tie in at the end of the video. It's extremely cool to see the ring lenses and their performance.

[@samk2407]

I just had a whole moment there when he said that the angle had to be bigger the smaller the spatial frequency we wanted to reproduce. That's such a simple explanation for the diffraction limit of a lens

[@71Kailee]

OMG what a fantatic demonstration of lens behaviour and diffraction limitation. Only a third of the way through the video but already it's an eye-opener and has made me finally truly understand some of the basic optical phenomena covered - even though I +thought+ I already understood them for decades. What a wonderful idea to connect up with Nils to create these superb graphics. Perfekte uitleg, beter kan het niet Jeroen!

[@Jay-sr8ge]

Always wondered why images get softer at the small apertures. This video explains it perfectly

[@smith507]

Bloody hell, my entire understanding of how lenses work was wrong all along! I learnt a lot from this video, thanks!

[@TheSidyoshi]

This is one of the best videos on KZbin.

[@DakiLund]

This perfectly explained my questions concerning "lens diffraction", thank you

[@MissNorington]

Awesome! Sticking around till the end of the video was very rewarding! It actually made sense seeing the real tests 🤯

[@TomatoBreadOrgasm]

Your work is on the same level as Applied Science, and I thought he was peerless. Now I have two answers for "what's the best science channel?" Nils is great, too, but a little niche. I'm very glad he directed me here.

[@AABB-px8lc]

Very satisfying explanation of NA, usually it too general and "dry", w/o motivation how it can be invented. Thanks.

[@not_just_burnt]

omg, the ASML teaser at the end was such a welcome surprise!!!

[@WolfmanDude]

I can say that I now understand the basic concept of nummerical aperture thanks to this video. I never understood how a aperture can have an effect on the image resolution, in my thinking it would only make the projected image less bright. Now I get it!

[@AnkitPatel-ih6uv]

This is one of the most fascinating videos I've watched! Connecting Fresnel lenses to fourier series and JPEG compression was quite mindblowing. Thank you so much for this great video!

[@alexpyattaev]

Your videos are by far superior to all of the courses on optics I have seen so far...

[@crownlands7246]

Wonderful walk-through, amazing visualization by Berglund 🙏 Looking forward to your visit at ASML 🌞

[@persianwhite]

The fact that I, who is dumb as a brick, can understand the presentation shows how well your content is made. Thank you, sir.

[@ENDESGA]

astonishing video - I wish I had this in high school. I understand optics a lot better now!

[@inifin8]

Looking forward to seeing ASML Lab

[@48ford8n]

This, like all your videos, is fantastic, I hope you make many more because this is one of my very favorite KZbin channels to watch.

[@anteshell]

This must be the best piece of information about how optics work I've even seen.

[@josefhrdlicka2251]

I'm studying optics in my masters and this video still contained an experiment I've seen for the first time. Fourier optics is fascinating. I believe you have made a video on Fourier transform and how ear can perform fourier transform. So basically if I understand it right, our eye is in fact also capturing just spacial frequencies of the things we see. It all comes together:)

[@satyris410]

I feel so lucky to have stumbled upon this KZbinr. I'm not an astronomer by any stretch, but that's where I came from - watching John Dobson making a reflector telescope from a porthole glass. I've learn so much about light already, thank you.

[@catbertsis]

This dudes goes on and on just shattering my understanding of physics and does not even sweat, somebody stop him! (actually nobody stop him I want more)

[@Scrogan]

Aha! That aperture explanation really snaps in place for me!

[@pixels_]

i have watched this channel for a long time, but today was a bit special -- i am in the photolithographic space and this was a wonderful illustration of the key concepts in my field. you almost have enough in this video to explain many important trends in semiconductor manufacturing for the last 20+ years in the principals covered here, which is of course where you are going in the next video! goede wetenschap :)

[@DiffractionLimited]

Excellent video, so interesting ! In the microscope footage, I really like how one can see slicies of the propagating light smoothly varying between an image of the aperture and an image of the object. Great work!

[@modus_ponens]

Omg omg so cool!! That's like applying inverse of diffraction pattern of a hole to create the hole. With all that fourier stuff, it's like magic!

[@daviasdf]

As an ASML employee and long time subscriber, I am exited about that teaser :)

[@SEThatered]

Thank you. I always was curious about this. But optics books are written so dry I couldn't make sense of it. You put it all into a very coherent narration.

[@DougMayhew-ds3ug]

Love the format and the “live from the bench” aspect. The unexpected 70’s music was a great gag. I almost dropped my phone. That was a brilliant tour through lenses and Fourier, and your deep hobby work on the photolithography slits makes it especially fulfilling to see unfold.

[@robertbass4590]

This video condensed several weeks of the Fourier optics lab I facilitated into an excellent 20 min video. Nice work!

[@fredfred2363]

This is so friggin obvious, but i'd never realised it. Thanks! And so well explained too.

[@larrydykes7643]

Wow that was fun! I get excited whenever I see a new post from you. THANKS!

[@futureboy7653]

Watched this and then the next suggested video was about computational lithography and there's literally the same circular lenses being used to better resolve a final mask image. Double mind-blower.

[@zorktxandnand3774]

You have a real talent for explaining complex matter in a way that makes it as easy to understand as possible. Great animation, script, and very good voice over with spot on timing. This coupled with the very practical experiments you set up make for top notch educational content. Your videos prove that education is not just stating facts, it is making knowledge understandable. Don't dumb down, but explain better! Well done sir!

[@EricJSmith-qe7cn]

Thank you for touching on Fresnel lenses. I own a 5 kW cine fresnel light and I could stare at the glass fresnel lens all day. I’m also fascinated with zone plate photography, so you hit a double whammy for me. I’ll be looking for more fresnel speak in your other videos, but please do more! :-)

[@larryscott3982]

The first 1/2 is really informative. I was pondering that issue for several just recently.

[@idontwantahandlethough]

Yesterday we celebrated Thanksgiving in the U.S. I am thankful for you and your wonderful videos, hope you have a good weekend dude 🤗 !

[@LoadBearingSolder]

Incredibly good video. This channel has taught me more about optics and physics than any other. I make optics and modules for ASML's lithography machines, and i cant wait for your next video. Im hoping it will give me the "why" behind the different specifications and techniques i have to follow to make these parts.

[@iestynne]

I worked in computer graphics (which is all about light transport and image formation) for 20 years, and I have learned so much new stuff from your videos. I can't express just how good they are. Thank you so much.

[@sinecurve9999]

Thanks for the excellent lecture. I highly anticipate your upcoming video on ASML. That's a very special visit. Cheers.

[@1337treats]

This video is so amazing. Thank you for the presentation of your content. It really improved my perspective on lenses and made the split light interference pattern so intuitive. I’ve been thinking about it for days. Beautiful.

[@JimGriffOne]

In terms of the intro scene (how light moves through a lens), when I look at light directivity now, I always think of it as perpendicular to the "rays", because it literally is based upon the way it moves. It's so difficult to imagine it in the old way any more, once you realise it's a perturbation of a continuum (the EM field) rather than straight lines pointing out in "rays". P.S. Those animations are awesome! Big up to Nils Berglund, and also big up to you for all your excellent and informative videos!

[@5ty717]

This is an excellent piece on the structural side of optics. However, one piece that you did on photonics has helped me more than any other. You explained that photons have a beginning and an end without a time like middle, and in this period their behaviour is that of a wave of probability direction and displacement. Only. My understanding is this complex plane wave continues until (strongly or weakly) absorbed in phase amplitude matched matter and harmonically reverberates (usually) the absorbing electron wave, in such a way as to mimic the established bandgap behaviour of electronic transitions Hence your clear representation of wave in some basis, rather than some sort of duality of a point particle has helped my understanding of much of photonics. Thank you for this. Jeroen you have some depth of understanding.

[@larvenfritson]

This was the most interesting thing I have watched in ages. Thanks for doing this!

[@EpsilonZRho]

Yet another amazingly informative video, Jeroen! I don't seem to recall you ever detailing in any of your previous videos the physical mechanism for index of refraction. Many of us would probably appreciate if you touched on it in a future video. I know I would!

[@lo-wokliya1267]

Brilliant, thanks for such much love and dedication and clarity

[@_abdul]

Just finished 3b1b's recent optics videos, This is absolutely a Treat to watch. Thanks for the amazing content.

[@yoonsikp]

This is the most interesting and my personal favourite channel on KZbin, thank you for your content.

[@djmips]

I feel like a changed man after watching this video. That's not often you can have such an effect with only a 20 minute video!

[@IslandHermit]

How timely. I was just looking yesterday to see if you had released any videos recently. Kudos to Nils for those fantastic animations, and kudos to you for such a clear and elegant explanation.

[@GerinoMorn]

I never understood fresnel lenses before. Now I do

[@ahaveland]

There is a difference - these are a special kind of Fresnel lenses crafted at the wavelength scale for diffraction. Fresnel lenses for lighthouses and TV screens are a much larger scale and still use refraction like normal lenses.

[@timschulz9563]

Thank you for this video! I had my personal moment of realization in university in my signals and systems lecture when we were introduced to the Fourier transform. I realized that decomposing a signal into discrete frequencies is basically the same thing a prism does.

[@kenwallace6493]

Top notch stuff! I never fail to be impressed. Carry on, sir!

[@spicken]

That is quite an achievement, indeed wonderful simulations. When I explain the effect of NA on resolution and depth of field having a video like this as 'further reading' is very useful. An alternative way to phrase it is that a positive lens is an exceptionally fast 2D Fourier transform i.e. a very fast computer. I'm sure you are aware of the community of pinhole camera enthusiasts. A 30 order zone plate would make a lot of people very happy.

[@rasherbilbo452]

More clearly done than most physics texts and lectures. Brilliant!

[@caleballen4721]

Absolutely incredible demonstrations. Both the simulations and the experiments. Thank you so much, this is extremely invigorating!

[@Rom2Serge]

Thank you for everything you are doing. Without any exaggeration , this is my most favorite channel on KZbin.

[@matze1508]

fantastic visualizations which underline the explanations very beautiful. Very excited for the next one :)

[@GregorShapiro]

I enjoy your deep dives into optics. I have been intrigued and enlightened by Nils Berglund's videos for a while now and recognized the reproductions you used here. Good job to you both!

[@lumotroph]

Brilliant video! Thank you for the clear explanation and good sense of humour 😅

[@chalkchalkson5639]

Next time on Huygens Optics: "The wave image of light is really just a rough approximation. [...] to give you a sense of when it fails, consider this setup involving a squeezed/number state. [...] here you can see a simulation of the LIGO interferometer with a coherent state and a squeezed state, as you can see [...]" :P This is some really excellent explanations of fairly advanced physics for a general audience! I love it! Especially the practical demonstrations are amazing :)

[@christiansinger2497]

Fascinating video! The effort you put in there to create such unique and informative content has my highest respect.

[@myself248]

Thank you for this! I just learned about liquid crystal diffractive optics, and this helped me get my head around a lot of the fundamentals of how they work. (And some of the higher-order effects, even!)

[@mmckinney]

Awesome to see the application of the wafer stepper for such a striking demonstration - great video!

[@ebrewste]

As always, an great optics video! I also want to compliment you on the clarity of presentation of such a difficult topic. This video made me reflect on the number of things you get right: optics, presentation, scripting, voiceover, weaving a story during a technical topic, editing, physical experiment, keeping the topic accessible for different levels, etc. A lovely accomplishment!!!

[@ajejebrazor4936]

Delightful! Thank you so so so much. This video needs to stay in the Hall of Fame of educational resources!!!

[@garybatch4102]

So well done and presented in an easy to understand, practical way. Twenty two and a half minutes of optical essentials flew by.. Looking forward to the next one...

[@josuelservin]

I already had most of the information about how this work, but this video finally made it all click together! What a wonderful gift, thank you so much for this amazing work.

[@SubTroppo]

Unless I have not been paying attention it has been a while, but it is worth the wait.

[@robertwatsonbath]

Really cool, thanks Jeroen. I was aware of Fresnel zone plate antennas but never stopped to think about how they really worked.

[@AK-vx4dy]

Definitely! You teach so wise things almost without effort. Great job !!!

[@siberx4]

Every video you put out is a treasure, and gives me new insights into phenomenon I either had not considered before, or thought I understood better than I did.

[@z0nx]

Ever since I played around with creating audio/music, I was always fascinated with those spectrum visualizers. Being able to see the parts that makes up the sound in time. Absolutely love to see so many sciencey videos essentially boiling down to just waves interacting and using the FFT. From black holes to audio to camera's/lenses, one day I will have to take the time to code up some implementation of FT myself and actually try to understand it. Dankewol for these amazing videos :)

[@AntiProtonBoy]

I love your channel. Your ability to explain optical phenomena is exceptional and is easy to follow.

[@bansci]

Did you just start a new internet flame war, jeepeg or jaypeg? It's gif all over again! Amazing insightful and humorous content again as always

[@pawelchmielniak3275]

Love your videos! Best (and seemingly only?) optics channel around!

[@faxezu]

Oh boy, every day a new Huygens video drops is a good one. And then also teasing a video with ASML as its topic, can't wait!

[@jobturner7925]

Outstanding video!! Truly changed the way I look at optics.

[@ronidaffan5904]

This is the most interesting youtube channel ever.

[@jontime59]

Amazing! I studied optics in college, but this was simply beautiful. Thank you.

[@smeggyhead1]

This is mind-blowing. Thank you

[@Nehekar1]

Thank you for your efforts here. Learning optics during my highschool with its oversimplifications made it look so unrelatable to me. Your channel offers such a deeper and more intuitiv way of showing the physics here. Thanks for that

[@Hexnilium]

Seems like this basically demonstrates that light is mostly a wave and that the particle aspect is much more abstract than it is a duality.

[@seabeepirate]

Light is weird! Very cool! Thanks for the clear explanation .

[@thurstonherricks738]

Thank you for producing these videos. They are enlightening and educational.