Can you give us a source for glass? Maybe an idea of what kind of glass to order so we can source it ourselves? I am in Oregon, my kids go to PSU where the original monolithic lenses were sent......
This series is easily the one I look forward to the most on UA-cam. Even if there's no way I could make such a thing, it's still brilliant to learn how it is done.
Been looking forward to part 2, can't wait for more! As an engineer, I find these technical deep-dives very interesting. Like last episode, please don't shy away from the maths, there's not enough technical content like this on youtube!
Thanks for this comment. I'm often in doubt about whether my video's are not too niche and technical. But I guess in this case it's partly what attracts a large fraction of the viewers.
@@HuygensOptics Viewers who don't care for the math can easily skip it. Everyone who appreciates the math cannot easily (or at all) watch the sections if they're left out.
I'm so damn happy that the original monolithic telescope video managed to get snagged by the algorithm. Without that I probably still would have no idea that this channel existed, and considering the amount of enjoyment I've gotten from watching these videos that would have been a shame. Your sense of humor is super on point, and many things in the presentation remind me of Techmoan, and I've always been interested in physics of all kinds, and the practical side of optics especially was always kind of dark art. It's easy to look at formulas and do calculations, and advanced computer controlled machinery can of course do wondrous things, but that's not how optics were developed originally. Seeing someone actually talking about and going through the physical process of making something by hand down to accuracies of tens of nanometers is just damn fascinating.
This series takes the genre of ”interesting step-by-step tutorials with no chance in hell of you actually doing it yourself” to a whole new level. We know you won’t build that cool shelf, ever, Jake. So why not fantasise about building your own non-spherical lens to view stars with?
Absolutely brilliant video. I studied optical engineering in the 90s, but ended up doing mostly software. I love seeing the "small workshop" approach to manufacturing such devices. Keep up the great work!
man, I don't know anything about optics and lenses but I opened your video out of curiosity because youtube recommended it to me and I listened to you carefully for 23 minutes like a child watching cartoons 🔝
Excellent work! I helped build the DKIST telescope on Maui, then worked at SpaceX and now I run the machine shop for Space Tango making science experiments for low earth orbit. You’ve inspired me to up my game.
Amazing how much we can achieve when daring to step outside the box we put ourselves in. As we often joked while working in wind tunnels: "this isn't rocket science -- oh, wait it actually is".
Not that long ago I was involved with redesigning the baffles for a 2 degree field of view 2.5 m telescope. It's not easy to baffle a telescope with this large a field and it required a baffle around the secondary, the hole in the primary, and third "floating" baffle in between. The Baffling could have been done with just a primary and secondary baffle but this would have greatly increased the obstruction, along with other difficulties. A light path was found that I was not initially expecting that required an addition to the primary baffle. This involved a bounce off the ID of the primary that was "shaded" by the secondary mirror, up to the secondary and down to the focal surface. It might have been a path that involved primary-secondary-primary-secondary-focus. Lots of bounces. It was a small effect but could be calculated. It was eliminated by just blocking the ID of the primary out to the diameter of the secondary, less the field of view. In your case this could probably be done by just not coating the primary all the way to the ID of the cored out area for the primary baffle. Probably such a small effect that it would never be noticed if it happens at all in your optical design. Great work and very interesting.
I have no idea why the UA-cam algorithm sent me here, I don't know anything about glass, but that's a pretty sweet rock you made and I'm glad i got to watch you do it
Huygen, I love your videos. Your type of change is what makes UA-cam and the internet such an amazing place - sharing really interesting stuff with each other. No matter the length, I’m glued to your videos. The articulation of the concepts are fantastic and the practical side is wonderful to see! Thank you for your hard work making these videos, I truly appreciate them.
I'm a chemist and I understand almost completely nothing about optics, but UA-cam just recommended this to me and it was a very interesting to watch. I'm looking forward to the next video.
My favorite is his actual measurements of Dual slit diffraction patterns in 3 dimensions. It provides intuitive insight including surprising real world subtleties. You see exactly what is happening including the lab set up even down to verifying the calibration.
I am a manufacturing engineer that knows a fair bit about metal machining but next to nothing about optics. I feel I was attacked by a tsunami of knowledge and information. I like your style! You just found a new subscriber.
Sir. You are Very, Very Much Appreciated for generating this body of work. The design and execution is excellent. Your most outstanding skill is in the description and explanation, and in this you rank among the very finest. As an Optical Technician (retired), tasked with making spherical and toric lenses for spectacles, in extreme positive and minus, and also as an amateur telescope maker, (refractive and reflective), listening to you is just Peachy Keen!
When I left school I applied for a job as a lense grinder with a military establishment. I had no idea. This video is amazing and totally incomprehensible to me.
I've blown Alot of glass and also milled and turned a bunch of metal, also turned wood. Never got into machining of glass beyond being aware that lenses were ground. This level of machining is amazing!
15:42 And here I was nerdgasming with all the precious info, and got hit with this gem... But seriously, I've been in love since part one, with the format full of details about something that I have only dreamt of DIY-ing. Keep up this marvelous job.
At last, my most anticipated video on UA-cam. It's great that you include the formulas. Even if I don't work through the numbers myself, the graphical representation is explained. This time, seeing just how you physically grind the correct radii was fascinating. I can't wait for the next one!
I'm honored to be able to witness this process (this is my second video watched. First one being Part-1) and in awe of your skills and technical equipment. Thanks for sharing. This is exactly what elevates UA-cam above the ordinary and makes watching it worthwhile in the long run. Learning and expanding the Horizon. Thrilling.
Totally amazing exercise in Accuracy, skill and patience. This makes machining a high tolerance metal component seem like a kinder garden art project. I look forward to seeing more of this project and the process used.
As a guy constantly using bought optics, I will say - you are just amazing. i am extremely astonished to see such an expertise level in a "home laboratory"
@Huygens Optics I want to say thank you very much for the download link to the program you made in this video. Another thing I wanted to say was that it was awesome to see you go from very serious explanations and such on the topic of the Monolithic Telescope, to what was easily one of my favorite parts of this video. It seemed to provide a much needed comic relief and hook to keep interest for those who might not have otherwise been so interested. "Spherotronic!!!!" That was hilarious!
Thank you for this amazing video series! As a master's student in physics and astro, I have never been able to actually delve in to the rich practical aspects of the optics. This series is a goldmine for people like us who love to learn. Keep up amazing work mate!
Found these videos because I love astronomy and the telescopes that allow my feeble eyes and brain to see and wonder. Traditionally these kind of videos are way too technical for me. That said I’m completely fascinated by these miniature optics and this amazing artisan mixing science, maths and good old hands on skills so we all can see a little more. Thank you
Another amazing video in the series! Can't wait for the next one. Content that goes into the technical details and the math like this is really rare on youtube, but the amazing details are what make these videos so good.
Beautiful dance moves!! :) Excellent video as always. I'm grinding and polishing my (very amateur) telescope mirror and was very happy to see how the mirror making process is made at a professional level. Thank you.
The less parts, the better durability and cheaper production. That's honestly not only a passion project, as some would say, but a very valuable R & D project for optics, indeed like you mentioned sometimes. Very thoughtful design.
Thank you for your clear and well-organized explanations. I was truly interested in optics and thrilled to learn about this integrated telescope lens production method. Thank you again, and will be waiting for more educational videos.
Hello and welcome to the outskirts of the internet. Away from the mainstream, the videos here are smart, meaningful, real and insightful, perhaps something you've never even thought about, or you didn't know was possible. You have no idea how you got here, you are neither a machinist nor an astronomer, yet you will watch this video start to end. It bears a surprise. Safe travels!
What an amazing project ! It amazes me how precise something can be made with the human hand and tools, thank you for sharing your knowledge and experience with us !
Fantastic video! I am not at all setup for working with glass, but with a couple of CNC milling machines in my shop I now really want to try making some first surface mirrors out of aluminum... A useless project perhaps, but I'm sure I would learn a lot!
Alu is doomed to unsatisfaction because of thermal expansion, and the only way to "recoat" it is by repolishing, but milling a honeycomb structure in the back of the billet would improve the stiffness/weight ratio. After milling a parabolic surface, maybe you could grind, measure and then even polish with the CNC too with an array of custom tooling. When you perfect that, you could try the same gcode on glass.
It's definitely useful. Think about that! The main benefit of Cassegrain (exactly the Schmidt-Cassegrain solution) optics is that a long focal length can be achieved with short build. Plus imagine if all of this is made of a solid piece, how shockproof is it! It’s just a matter of size, how many areas it can be used. In kind of sensors in vibrating environment, military purposes, even in mobile phone cameras or just for even more durable telescopes or binoculars.
It simply amazes me that there are such experts in whatever field you can think of. You knowledge is truly mind-blowing and you even make it interesting to a complete layman like me.
Everything in this series is fascinating, and I look forward to learning more about this in the next instalment! It is astonishing what dedication and knowledge can accomplish.
We noticed the injection of little human touches and humor, like the fish on the plastic bag shield and the DJ scene. Just shows you that science doesn't have to be sterile. Well Done!
Absolutely incredible work, again. Don't stop making videos. I run an astronomy Nonprofit and a couple teem members make 24in-32 inch mirrors for visual application, but this is the opposite, and fascinates me.
Very interesting. As a mold and die maker, it is intriguing to see how you work your way up to optical precision. The process for cutting glass is quite different. Thank you for sharing.
First off, fantastic work, thanks for sharing this; second I had to pause the video to click “like”. RIGHT NOW for the ultra spherotronic intro section! 🤣
If you have accurate mounting plates, you can also start drilling on one side and then turn over and drill through from the other. Sometimes tape can help with splintering on the starting surface.
I was wondering how it would look with the spherical surfaces, thanks for showing! This series is so interesting, your production quality and method of teaching are also top notch imho. Looking forward to episode 3!
Amazing video as always, it's midnight here and I still put on my glasses and booted the laptop to watch it, love the balance of technical, showing the real challenges rather than the finished product, and humour. Yes I'd be interested in maths deep dive / zemax, but I think it's wise to keep it streamlined as you have so it doesn't turn off a semi-technical or non-technical audience, can always make a deep dive video or second channel (to not hurt your priority in the algorithm with a potentially lower-engagement video). I've worked on some micro high-precision optics myself, and I'm surprised that you're using spherometers of any ultimateness once you're sub 50 micron. With parts that small, it is near impossible to achieve accurate measurement with no flexing of the glass or substrate, and then the adhesive is either flexible and soft, or hard and scratching, both which hurt your results. And then you start to run into problems of different pockets of slightly different densities in the glass creating different distortions, somewhat based on temperature, and so all you can hope to get to is 'mathematically perfect', which may not correlate to optically perfect below f4. Is there any reason you wouldn't make an interferometer-style checking apparatus, akin to schlieren imaging? I know that means you have to keep removing compound, but that can be automated with a high pressure distilled water wash, and then you're checking the results in the optical domain, where results are quantifiable in more metrics, and with results that are more directly relevant to the end product? Even having a 4k monitor imaged on to a screen with 20MP camera would probably be sufficient if combined with aperture control. Can be a normal 'camera obscura' style, or you can get fancy and use a 4F correlator setup (provides better linearity to the results you measure vs material removal location estimation). My bet is that stopped down this lens will come together wonderfully, but wide open is going to impossible in BK7 with cerium. I'd think through how to make a temporary aperture for measurements - silver laid down in concentric rings, tiny gaps, then you can vaporise them with high-current low voltage (thermals could be risky, glass has to be preheated), or just reclaim the silver using an anodic cotton tip with an electrolyte that can accept the silver only upon high voltage application to that ring. And don't limit it to a simulation of a normal lens aperture, it allows you to test bands of the lens and chase down sources of imprecision, so I'd start with testing the peripheries and remove reflector from the inside first. In fact, to speed up tests you could actually utilise the 5% reflection of the uncoated glass boundry, masking off lost light externally, but then you can make a series of rods of the same glass with roughly the same inverse curvature on one end, and a sharp angle on the other, in increasing diameters representing the F-stops going F5.6, F4, F2.8, etc, glued with a water soluble low strength Norland optical adhesive to the lens, and then you black paint the furthest out half of the rod to absorb all transmitted light (100% loss waveguide). The glue if it matches the OD of your glass will mean the rods only need to be roughly in the right shape. Then testing is a breeze, modern high ISO cameras can deal with the reduced light output even if it was down to 1%, and the results would be representative of what would be achieved with sputtered mirror without having to redo the coating so often. I think you'll find that akin to the contrast lost in a fresnel lens from the percentage of surface area taken up by diffraction points, your lens has considerable diffraction point area I think, not simple to 'black paint' out because the boundary of course creates new areas of diffraction. I would test the impact of this by double masking the incoming light at 5cm and 10cm from the lens, so that the light only falls upon the non-sharp-radiused parts of the glass. Also the black paint you use can have a dramatic difference with how much TIR style reflection happens on the peripheries, and how much is absorbed - normally I paint an ordinary household drinking glass on the outside, then see how much light escapes when illuminated from within with a torch or laser - can fill with water or oil to minimise reflections of the internal glass boundry. Most black paints when they dry do not perfectly adhere to the glass, and the tiny pockets of gaps that emerge turn a 97% black paint into more like 92%, because they are almost always designed to be darkest on the non-substrate air side. Especially true of 'vantablack' or any black that relies on surface structure to cause light to bounce multiple times between the 'skyscrapers'. The 'skyscraper' effect can be reproduced by the right paint combined with 'roughing up' the painted areas. They are hazardous to work with, but acids that work similarly to hydrofluoric acid (very low molarity, highly localised, neutralizing agent constantly applied) to get past the sub-micron cracking while polishing issue where its critical on the periphery might be worth investigating. The right acid for the right glass allows the 'tips' to be preferentially embrittled, and so finer pieces are ablated more from the areas you want with less cracking of the good bits you want to keep (more accurately, you are changing the speed of sound in the tips as you impregnate the glass, and so impedance matching with the bulk glass is decreased, reducing crack propagation by reflecting more of the energy back in to the tips). Sometimes it is necessary to apply a protective non-miscible hydrocarbon that preferentially wets the 'valleys', concentrating the acid to the 'hills, and adding a hydrocarbon removing compound that is embedded in the solid polishing media (so keeping the hydrocarbons constrained to the valleys). You're probably already familiar, but I think you're on your way to acquiring an SPDT machine eventually, but even before then have a look at the patents and the types of glasses used, I think you'll find it relevant to your manual processes also. Lastly, I know this is jumping the gun a little, but for the final-product mirrors, by using sputtered metal you're missing an opportunity for chromatic aberration correction. With careful controlled application of AR coatings, you can have different wavelengths penetrate into the reflector to different depths, providing a slightly different travel distance or even a slightly different curvature. Again the patents on CHIRP laser processes and multi-wavelength laser cavities are where I think I have read the most relevant material. Anyway, such a great channel and project, can't wait for future installments.
I’d love to see the response to your comment … I never heard of anti reflective coatings affecting the path length as a function of wavelength, just reflectivity as a function of wavelength. I suppose if the multilayered anti reflective coating that is optimized to pass a particular wavelength is hit with a different wavelength, then the reflections are more likely to be off the top layer, implying the bending of the ray may be closer to the top layer than the middle layer. Another way of saying the same thing is to claim the anti reflective coating has an index of refraction that changes as a function of wavelength. Since the anti reflective coating thickness may be 20 wavelengths long, I see how this would affect chromatic aberration. Also, it implies the index of refraction of the anti reflective coating would change as a function of the angle of the light ray. For perfect optics calculations I would expect this to be addressed (perhaps the magnitude of phase shifts in the wavefront is much less than a tenth wavelength).
@@douginorlando6260 I'd love to see a response too, that's my favourite part of youtube, when viewers give back to the channel. Re: wavelength specific coatings, also worth checking out Foveon sensors. While not directly applicable here (absorbs rather than reflects), it is a commercialised product that functions based on penetration depth being related to wavelength. RP photonics has a great article on 'Bragg mirrors' and although I wouldn't implement their examples (because they are so angle of incidence sensitive, so would change their correction dependent on how close to small aperture / pinhole the device was operated), it shows the key principles.
This is a great thread of comments perhaps even needs its own Reddit page. Hoping to see how HD Raspberry Pi camera w/rpi0 can be integrated. And of course who can step up with automated AI Mfg of monolithic telescope technology. Yes, I know the strong held belief of manual mfg.
@@energyideas thanks very much! Don't think he's going to reply, probably threw too many ideas out there, causes the channel creator to have one of these reactions - I should properly respond to this point by point, I shall press snooze on that mammoth task till I have enough spare time, probably around 2051 - Hmm close but not quite, so I'll either insult their inteligence or come across as unappreciative and alienate other viewers, maybe just ignore it - Nooo there are some good ideas in there, so now if I acknowledge the comment and implement them, he'll think I'm copying his ideas. Was hoping to patent some of this process, does this comment invalidate all my avenues for protection. Best to shut my eyes Again nothing to do with this creator, he's probably just really busy, but a trend I've noticed on UA-cam
Very cool project. My father is a laboratory glass instrument maker so ive seen a lot of the processes and tools being used and it kid of makes me want to try this ... if only i had the time.
Brilliant! Super interesting and usefull, thank you SO much for your knowledge and sharing efforts! Can't wait to see next episodes. Personally working in a precision metrology field and find your results amazing.
Dancing lesson classes are now fully booked for 2022.
No one else but a optical engineer has so precise moves 😂😂
I have been EAGERLY awaiting this....
Yessss❤️😎
Can you give us a source for glass? Maybe an idea of what kind of glass to order so we can source it ourselves?
I am in Oregon, my kids go to PSU where the original monolithic lenses were sent......
Where can we buy the record Spherotronic? i like the music video. I am looking forward to the vapor coating and the pitch patterns
Wow, incredible project. Thanks for sharing your knowledge and experience so clearly!
And reflectively!
Evidently the life of an optical expert is kind of a grind....
@@4n2earth22 But it polishes up nicely! 😃
@@Hydrazine1000 @4n 2earth - goddemit you guys, god demmit!!!=)
As I was watching I thought .. 'SMH would love this guy'.
Now I'm wondering how you could integrate a "Wife Mode" into a telescope.
That ultra sphereotronic should be a staple of every reputable discotheque in the world.
I am almost insulted there was no link to a soundcloud page
That's the absolute most inappropriate thing I've ever heard anyone say, ever.
Discos still exist!?
@@tubedude54 i think they are called MP3otheques Now but the concept is similar
This series is easily the one I look forward to the most on UA-cam. Even if there's no way I could make such a thing, it's still brilliant to learn how it is done.
I agree. It is such a monumental task, that I have the utmost respect for someone who even attempts it, let alone succeeds
I absolutely second this
Hear hear!
The 15:45 moment caught me off guard. Thanks for sharing your process with so much detail and fun bits. It makes it twice as enjoyable.
Been looking forward to part 2, can't wait for more! As an engineer, I find these technical deep-dives very interesting. Like last episode, please don't shy away from the maths, there's not enough technical content like this on youtube!
Thanks for this comment. I'm often in doubt about whether my video's are not too niche and technical. But I guess in this case it's partly what attracts a large fraction of the viewers.
@@HuygensOptics Possibly make the technical asides clear sections and note timestamps to skip them for uninterested viewers?
@@bachaddict Similar to how CuriousMarc does his elevator music technical interludes?
@@HuygensOptics Viewers who don't care for the math can easily skip it. Everyone who appreciates the math cannot easily (or at all) watch the sections if they're left out.
@@HuygensOptics I think you shouldn't hold back on the technical aspects, as long as they're of interest to you.
I'm so damn happy that the original monolithic telescope video managed to get snagged by the algorithm. Without that I probably still would have no idea that this channel existed, and considering the amount of enjoyment I've gotten from watching these videos that would have been a shame. Your sense of humor is super on point, and many things in the presentation remind me of Techmoan, and I've always been interested in physics of all kinds, and the practical side of optics especially was always kind of dark art. It's easy to look at formulas and do calculations, and advanced computer controlled machinery can of course do wondrous things, but that's not how optics were developed originally. Seeing someone actually talking about and going through the physical process of making something by hand down to accuracies of tens of nanometers is just damn fascinating.
This series takes the genre of ”interesting step-by-step tutorials with no chance in hell of you actually doing it yourself” to a whole new level.
We know you won’t build that cool shelf, ever, Jake. So why not fantasise about building your own non-spherical lens to view stars with?
But hey if I run out of hobby ideas in about 10 years, I'm gonna have a banger go-to idea
I thought that about his Round Spirit-Level a Year ago...
well, im grinding one right now myselfe :P
@@T1g3rch3n You go man, good luck :D
Unless you go out and start trying to build a shelf, you'll never get to the optics. Get your hands dirty!
LOL I was thinking the same thing as I watched.
Absolutely brilliant video.
I studied optical engineering in the 90s, but ended up doing mostly software. I love seeing the "small workshop" approach to manufacturing such devices.
Keep up the great work!
Oh man this is so satisfying to watch!
As a technic nerd myself, I could watch you all day.
Thank you for sharing this!
man, I don't know anything about optics and lenses but I opened your video out of curiosity because youtube recommended it to me and I listened to you carefully for 23 minutes like a child watching cartoons 🔝
Excellent work! I helped build the DKIST telescope on Maui, then worked at SpaceX and now I run the machine shop for Space Tango making science experiments for low earth orbit. You’ve inspired me to up my game.
Amazing how much we can achieve when daring to step outside the box we put ourselves in.
As we often joked while working in wind tunnels: "this isn't rocket science -- oh, wait it actually is".
Awesome, I am currently working on a project utilizing a space tango cubelab as the mechanical Container 😃
@@NHeinz Man what a small world.
Not that long ago I was involved with redesigning the baffles for a 2 degree field of view 2.5 m telescope. It's not easy to baffle a telescope with this large a field and it required a baffle around the secondary, the hole in the primary, and third "floating" baffle in between. The Baffling could have been done with just a primary and secondary baffle but this would have greatly increased the obstruction, along with other difficulties.
A light path was found that I was not initially expecting that required an addition to the primary baffle. This involved a bounce off the ID of the primary that was "shaded" by the secondary mirror, up to the secondary and down to the focal surface. It might have been a path that involved primary-secondary-primary-secondary-focus. Lots of bounces. It was a small effect but could be calculated. It was eliminated by just blocking the ID of the primary out to the diameter of the secondary, less the field of view. In your case this could probably be done by just not coating the primary all the way to the ID of the cored out area for the primary baffle. Probably such a small effect that it would never be noticed if it happens at all in your optical design.
Great work and very interesting.
I have no idea why the UA-cam algorithm sent me here, I don't know anything about glass, but that's a pretty sweet rock you made and I'm glad i got to watch you do it
Huygen, I love your videos. Your type of change is what makes UA-cam and the internet such an amazing place - sharing really interesting stuff with each other. No matter the length, I’m glued to your videos. The articulation of the concepts are fantastic and the practical side is wonderful to see! Thank you for your hard work making these videos, I truly appreciate them.
Can't wait for part 3. Really interesting.
I'm a chemist and I understand almost completely nothing about optics, but UA-cam just recommended this to me and it was a very interesting to watch. I'm looking forward to the next video.
My favorite is his actual measurements of Dual slit diffraction patterns in 3 dimensions. It provides intuitive insight including surprising real world subtleties. You see exactly what is happening including the lab set up even down to verifying the calibration.
I am a manufacturing engineer that knows a fair bit about metal machining but next to nothing about optics. I feel I was attacked by a tsunami of knowledge and information. I like your style! You just found a new subscriber.
Wow! The engineering and labor behind these devices continues to amaze! Great work!
Sir. You are Very, Very Much Appreciated for generating this body of work. The design and execution is excellent. Your most outstanding skill is in the description and explanation, and in this you rank among the very finest. As an Optical Technician (retired), tasked with making spherical and toric lenses for spectacles, in extreme positive and minus, and also as an amateur telescope maker, (refractive and reflective), listening to you is just Peachy Keen!
The knowledge, skills and craftsmanship you own just blows my mind, I salute you my kindly sir
Videos such as this are what make UA-cam great. Can't wait to dive deeper in the next one!
When I left school I applied for a job as a lense grinder with a military establishment. I had no idea. This video is amazing and totally incomprehensible to me.
I've blown Alot of glass and also milled and turned a bunch of metal, also turned wood. Never got into machining of glass beyond being aware that lenses were ground. This level of machining is amazing!
15:42
And here I was nerdgasming with all the precious info, and got hit with this gem...
But seriously, I've been in love since part one, with the format full of details about something that I have only dreamt of DIY-ing. Keep up this marvelous job.
Thank you very much for sharing your curiosity, knowledge and peculiar craftsmanship with us. Can’t wait to see new episode. 🙏🏻
What an absolutely spectacular series. I cannot wait for the next one
Impressive results, even with the aberrations! Looking forward to more
At last, my most anticipated video on UA-cam. It's great that you include the formulas. Even if I don't work through the numbers myself, the graphical representation is explained. This time, seeing just how you physically grind the correct radii was fascinating. I can't wait for the next one!
I'm honored to be able to witness this process (this is my second video watched. First one being Part-1) and in awe of your skills and technical equipment. Thanks for sharing. This is exactly what elevates UA-cam above the ordinary and makes watching it worthwhile in the long run.
Learning and expanding the Horizon. Thrilling.
The sharing of Knowledge - this is why I love UA-cam.
Totally amazing exercise in Accuracy, skill and patience. This makes machining a high tolerance metal component
seem like a kinder garden art project. I look forward to seeing more of this project and the process used.
I have no idea how I got recommended this, but your presentation style is excellent. I watched every moment.
As a guy constantly using bought optics, I will say - you are just amazing. i am extremely astonished to see such an expertise level in a "home laboratory"
wow, just wow... I'm speechless, that's some glass magic right there - all those measurements and processing are just wild, great job!
@Huygens Optics I want to say thank you very much for the download link to the program you made in this video. Another thing I wanted to say was that it was awesome to see you go from very serious explanations and such on the topic of the Monolithic Telescope, to what was easily one of my favorite parts of this video. It seemed to provide a much needed comic relief and hook to keep interest for those who might not have otherwise been so interested. "Spherotronic!!!!" That was hilarious!
Excellent work, and thanks for letting us have a look through it! I am captivated by this idea of monolithic telescopes.
Thank you for this amazing video series! As a master's student in physics and astro, I have never been able to actually delve in to the rich practical aspects of the optics. This series is a goldmine for people like us who love to learn. Keep up amazing work mate!
Found these videos because I love astronomy and the telescopes that allow my feeble eyes and brain to see and wonder. Traditionally these kind of videos are way too technical for me. That said I’m completely fascinated by these miniature optics and this amazing artisan mixing science, maths and good old hands on skills so we all can see a little more. Thank you
Jesus christ, I was *not* expecting the SPHEROTRONIC. That made my day. Really cool work, looking forward to the next part.
Another amazing video in the series! Can't wait for the next one. Content that goes into the technical details and the math like this is really rare on youtube, but the amazing details are what make these videos so good.
This really brings back memories for me. I was a lens and mirror maker in the 60s. You have a beautiful shop.
That spherotronic bit was fire. Thank you for enriching our lives
you talk above my education about half the time, but you always bring it around to understanding a bit later. +1
Beautiful dance moves!! :) Excellent video as always.
I'm grinding and polishing my (very amateur) telescope mirror and was very happy to see how the mirror making process is made at a professional level.
Thank you.
Wow, just wow! Looking forward to the next video instalment.
The less parts, the better durability and cheaper production. That's honestly not only a passion project, as some would say, but a very valuable R & D project for optics, indeed like you mentioned sometimes. Very thoughtful design.
This is some exquisite engineering! Thank you for sharing the genius approach to making these incredible optics!
Absolutely wonderful. Level of accuracy and knowledge is astounding.
Thank you for your clear and well-organized explanations. I was truly interested in optics and thrilled to learn about this integrated telescope lens production method.
Thank you again, and will be waiting for more educational videos.
I'm simply astonished, !!! I love clickspring videos for the mecanics and i think I found its optical counterpart
This is a true gem of content, and we are early enjoyers. Thanks!
Hello and welcome to the outskirts of the internet. Away from the mainstream, the videos here are smart, meaningful, real and insightful, perhaps something you've never even thought about, or you didn't know was possible. You have no idea how you got here, you are neither a machinist nor an astronomer, yet you will watch this video start to end. It bears a surprise. Safe travels!
What an amazing project ! It amazes me how precise something can be made with the human hand and tools, thank you for sharing your knowledge and experience with us !
Fantastic video! I am not at all setup for working with glass, but with a couple of CNC milling machines in my shop I now really want to try making some first surface mirrors out of aluminum... A useless project perhaps, but I'm sure I would learn a lot!
Nothing is useless if it gives you the opportunity to learn. Good luck!
Alu is doomed to unsatisfaction because of thermal expansion, and the only way to "recoat" it is by repolishing, but milling a honeycomb structure in the back of the billet would improve the stiffness/weight ratio.
After milling a parabolic surface, maybe you could grind, measure and then even polish with the CNC too with an array of custom tooling. When you perfect that, you could try the same gcode on glass.
It's definitely useful. Think about that! The main benefit of Cassegrain (exactly the Schmidt-Cassegrain solution) optics is that a long focal length can be achieved with short build. Plus imagine if all of this is made of a solid piece, how shockproof is it! It’s just a matter of size, how many areas it can be used. In kind of sensors in vibrating environment, military purposes, even in mobile phone cameras or just for even more durable telescopes or binoculars.
@@tamasau8725 I was not saying the monolithic telescope was useless, I was saying my aluminum mirror project was useless!
@@GoughCustom OK. Sorry, I misunderstood you.
Thank you for making youtube a great place. I love your project.
15:43 SPHEROTRONIC moment caught me by surprise
It simply amazes me that there are such experts in whatever field you can think of. You knowledge is truly mind-blowing and you even make it interesting to a complete layman like me.
Everything in this series is fascinating, and I look forward to learning more about this in the next instalment! It is astonishing what dedication and knowledge can accomplish.
The spherotronic bit was so surprising and delightful!
It is genius to add ultra sphereotronic dance into the serious educationsl video! Thank you so much! It was awsome! :D
This is mind blowing, real engineer in action. Cool to see such content.
Phenomenal work (and dance moves)! Thank you for sharing!
This was such a great video, the merging of practical information with light hearted humor is done impeccably, I am hooked!
Showing the image produced before the aspherical contours are polished was very illuminating.
This is a fantastically done video. This tech will go far and be used for many things. Imagine if mass manufacturing could be figured out.
i love the unexpected departure from theory to a quick improvised tool praising techno music interlude. well done :D
Amazing project. That spherotronic bit was so unexpected and hilarious you've got my sub!
I am not sure you realize how amazing your videos are...
We noticed the injection of little human touches and humor, like the fish on the plastic bag shield and the DJ scene. Just shows you that science doesn't have to be sterile. Well Done!
Learning is one of the many great joys of life. Thank you for sharing
Absolutely incredible work, again. Don't stop making videos. I run an astronomy Nonprofit and a couple teem members make 24in-32 inch mirrors for visual application, but this is the opposite, and fascinates me.
Just came to this channel, loved part 1 but the spherotronic dance immediately upped this channel to my top 10 😂
As an optician I am very impressed. All thumbs up👍👍👍
Excellent video, great in-depth description of the precision required for the manufacturing process.
Mijneer, this is fkin amazing. I had no real interest in optics or applications for any of it but i can't stop watching a true master of their art.
This is so far away from anything I would ever do but its absolutely fascinating none the less
Thanks for going the extra mile and silvering the unfinished surfaces.
Very interesting. As a mold and die maker, it is intriguing to see how you work your way up to optical precision. The process for cutting glass is quite different. Thank you for sharing.
Such an amazing project. Thanks for bringing us along with you!
That 90s Spherotronic edit was too funny! Thank you for taking me by surprise :D
Amazing work, love this window into a dark art
First off, fantastic work, thanks for sharing this; second I had to pause the video to click “like”. RIGHT NOW for the ultra spherotronic intro section! 🤣
If you have accurate mounting plates, you can also start drilling on one side and then turn over and drill through from the other. Sometimes tape can help with splintering on the starting surface.
your videos are so well-polished
I was wondering how it would look with the spherical surfaces, thanks for showing! This series is so interesting, your production quality and method of teaching are also top notch imho. Looking forward to episode 3!
This is incredible! I had no idea there was all these custom techniques for polishing.
Soo much knowledge and skill, spilled out in one video. Amazing. Thanx
The force is strong on you. thanks for the magnific video.
Thanks for sharing these wonderful video's, more detailed knowledge always leads to better understanding.
Awesome work, I'm loving this series...cheers.
So interesting
This is amazing in every aspect - explaining and craftsmanship. Much respect to you, Sir.
Another great video! You are an excellent craftsman and teacher. Thank you.
Amazing video as always, it's midnight here and I still put on my glasses and booted the laptop to watch it, love the balance of technical, showing the real challenges rather than the finished product, and humour. Yes I'd be interested in maths deep dive / zemax, but I think it's wise to keep it streamlined as you have so it doesn't turn off a semi-technical or non-technical audience, can always make a deep dive video or second channel (to not hurt your priority in the algorithm with a potentially lower-engagement video).
I've worked on some micro high-precision optics myself, and I'm surprised that you're using spherometers of any ultimateness once you're sub 50 micron. With parts that small, it is near impossible to achieve accurate measurement with no flexing of the glass or substrate, and then the adhesive is either flexible and soft, or hard and scratching, both which hurt your results. And then you start to run into problems of different pockets of slightly different densities in the glass creating different distortions, somewhat based on temperature, and so all you can hope to get to is 'mathematically perfect', which may not correlate to optically perfect below f4.
Is there any reason you wouldn't make an interferometer-style checking apparatus, akin to schlieren imaging? I know that means you have to keep removing compound, but that can be automated with a high pressure distilled water wash, and then you're checking the results in the optical domain, where results are quantifiable in more metrics, and with results that are more directly relevant to the end product? Even having a 4k monitor imaged on to a screen with 20MP camera would probably be sufficient if combined with aperture control. Can be a normal 'camera obscura' style, or you can get fancy and use a 4F correlator setup (provides better linearity to the results you measure vs material removal location estimation).
My bet is that stopped down this lens will come together wonderfully, but wide open is going to impossible in BK7 with cerium. I'd think through how to make a temporary aperture for measurements - silver laid down in concentric rings, tiny gaps, then you can vaporise them with high-current low voltage (thermals could be risky, glass has to be preheated), or just reclaim the silver using an anodic cotton tip with an electrolyte that can accept the silver only upon high voltage application to that ring. And don't limit it to a simulation of a normal lens aperture, it allows you to test bands of the lens and chase down sources of imprecision, so I'd start with testing the peripheries and remove reflector from the inside first. In fact, to speed up tests you could actually utilise the 5% reflection of the uncoated glass boundry, masking off lost light externally, but then you can make a series of rods of the same glass with roughly the same inverse curvature on one end, and a sharp angle on the other, in increasing diameters representing the F-stops going F5.6, F4, F2.8, etc, glued with a water soluble low strength Norland optical adhesive to the lens, and then you black paint the furthest out half of the rod to absorb all transmitted light (100% loss waveguide). The glue if it matches the OD of your glass will mean the rods only need to be roughly in the right shape. Then testing is a breeze, modern high ISO cameras can deal with the reduced light output even if it was down to 1%, and the results would be representative of what would be achieved with sputtered mirror without having to redo the coating so often.
I think you'll find that akin to the contrast lost in a fresnel lens from the percentage of surface area taken up by diffraction points, your lens has considerable diffraction point area I think, not simple to 'black paint' out because the boundary of course creates new areas of diffraction. I would test the impact of this by double masking the incoming light at 5cm and 10cm from the lens, so that the light only falls upon the non-sharp-radiused parts of the glass. Also the black paint you use can have a dramatic difference with how much TIR style reflection happens on the peripheries, and how much is absorbed - normally I paint an ordinary household drinking glass on the outside, then see how much light escapes when illuminated from within with a torch or laser - can fill with water or oil to minimise reflections of the internal glass boundry. Most black paints when they dry do not perfectly adhere to the glass, and the tiny pockets of gaps that emerge turn a 97% black paint into more like 92%, because they are almost always designed to be darkest on the non-substrate air side. Especially true of 'vantablack' or any black that relies on surface structure to cause light to bounce multiple times between the 'skyscrapers'. The 'skyscraper' effect can be reproduced by the right paint combined with 'roughing up' the painted areas.
They are hazardous to work with, but acids that work similarly to hydrofluoric acid (very low molarity, highly localised, neutralizing agent constantly applied) to get past the sub-micron cracking while polishing issue where its critical on the periphery might be worth investigating. The right acid for the right glass allows the 'tips' to be preferentially embrittled, and so finer pieces are ablated more from the areas you want with less cracking of the good bits you want to keep (more accurately, you are changing the speed of sound in the tips as you impregnate the glass, and so impedance matching with the bulk glass is decreased, reducing crack propagation by reflecting more of the energy back in to the tips). Sometimes it is necessary to apply a protective non-miscible hydrocarbon that preferentially wets the 'valleys', concentrating the acid to the 'hills, and adding a hydrocarbon removing compound that is embedded in the solid polishing media (so keeping the hydrocarbons constrained to the valleys). You're probably already familiar, but I think you're on your way to acquiring an SPDT machine eventually, but even before then have a look at the patents and the types of glasses used, I think you'll find it relevant to your manual processes also.
Lastly, I know this is jumping the gun a little, but for the final-product mirrors, by using sputtered metal you're missing an opportunity for chromatic aberration correction. With careful controlled application of AR coatings, you can have different wavelengths penetrate into the reflector to different depths, providing a slightly different travel distance or even a slightly different curvature. Again the patents on CHIRP laser processes and multi-wavelength laser cavities are where I think I have read the most relevant material.
Anyway, such a great channel and project, can't wait for future installments.
I’d love to see the response to your comment … I never heard of anti reflective coatings affecting the path length as a function of wavelength, just reflectivity as a function of wavelength. I suppose if the multilayered anti reflective coating that is optimized to pass a particular wavelength is hit with a different wavelength, then the reflections are more likely to be off the top layer, implying the bending of the ray may be closer to the top layer than the middle layer. Another way of saying the same thing is to claim the anti reflective coating has an index of refraction that changes as a function of wavelength. Since the anti reflective coating thickness may be 20 wavelengths long, I see how this would affect chromatic aberration. Also, it implies the index of refraction of the anti reflective coating would change as a function of the angle of the light ray. For perfect optics calculations I would expect this to be addressed (perhaps the magnitude of phase shifts in the wavefront is much less than a tenth wavelength).
@@douginorlando6260 I'd love to see a response too, that's my favourite part of youtube, when viewers give back to the channel. Re: wavelength specific coatings, also worth checking out Foveon sensors. While not directly applicable here (absorbs rather than reflects), it is a commercialised product that functions based on penetration depth being related to wavelength.
RP photonics has a great article on 'Bragg mirrors' and although I wouldn't implement their examples (because they are so angle of incidence sensitive, so would change their correction dependent on how close to small aperture / pinhole the device was operated), it shows the key principles.
This is a great thread of comments perhaps even needs its own Reddit page. Hoping to see how HD Raspberry Pi camera w/rpi0 can be integrated. And of course who can step up with automated AI Mfg of monolithic telescope technology. Yes, I know the strong held belief of manual mfg.
@@energyideas thanks very much! Don't think he's going to reply, probably threw too many ideas out there, causes the channel creator to have one of these reactions
- I should properly respond to this point by point, I shall press snooze on that mammoth task till I have enough spare time, probably around 2051
- Hmm close but not quite, so I'll either insult their inteligence or come across as unappreciative and alienate other viewers, maybe just ignore it
- Nooo there are some good ideas in there, so now if I acknowledge the comment and implement them, he'll think I'm copying his ideas. Was hoping to patent some of this process, does this comment invalidate all my avenues for protection. Best to shut my eyes
Again nothing to do with this creator, he's probably just really busy, but a trend I've noticed on UA-cam
Very cool project. My father is a laboratory glass instrument maker so ive seen a lot of the processes and tools being used and it kid of makes me want to try this ... if only i had the time.
I have no affinity with glass or lenses, but I still found your video informative as heck! Can't wait to see the dance moves in the next part!
Brilliant! I can't wait to see the end result!
That Ultra Spherotronic came very close to cost me a new cup of coffee. And Laptop.
Well done, I much appreciated that laugh!
Brilliant! Super interesting and usefull, thank you SO much for your knowledge and sharing efforts! Can't wait to see next episodes. Personally working in a precision metrology field and find your results amazing.