@@philiprowney I have a basic understanding about some of the things he was talking about, but struggled to keep up. I think an interesting follow up video could be eevblog (dave) giving a slowed down explanation about some of the points gav made.
The trouble is like he said, we don't see polarisation... so we don't really understand it well. So you need to understand the requisites, unfortunately
great video. I'd also like to add that I appreciate the couple extra seconds at the end of each video, so I can pause it to like or comment before my playlist continues. I wish more people did that.
fyi, the abbreviations: ......................... Polarized A = Anti-diagonal D = Diagonal H = Horizontal V = Vertical R = Right-hand circularly L = Left-hand circularly Myself, I didn't know what the A was there for
It's not really _that_ esoteric for anyone who has owned a halfway decent SLR & taken a photography class knows that one of the best filters you can add to your camera is a circularly polarized filter. You can rotate it and dial in or out how much effect you get. But, yes, it's great content and I'm sure they'll be some cool use for it eventually. I wouldn't mind seeing a Part II to this one. I didn't know about the other types of polarized light even existing until this video. Good Job Dave!
Truly amazing stuff! Can't wait to see the images from your camera... Your models are astonishing too - as a chemist working with optical molecules I never *fully* understood these relationships - would have loved to have these as tools! Good explanation regarding sugars too - it's worth noting that we're referencing a dextrose, or glucose, monosaccaride when referring to dextro and levorotatory properties. Sugar, a sucrose fructose disaccaride, or indeed any polysaccaride, will of course also display rotation characteristics as a function of their combined monosaccarides.
Your guest may be interested in Sony's IMX250MZR camera sensor with polarizer filter array over pixels instead of color filter array. There are machine vision camera products shipping with this sensor already.
That came out this year, still very new. And it's a single package that is the same as 4 cameras with 4 filters -- or what the DolPi project did with multiple exposures through different filters; better performance/cost but the learning was done by tinkering here
Sure, learning by tinkering is better, but only up to a certain point. There is a reason we've come so far technologically and it's because we have access to all the information that was written down before our time. If every human had to start everything over from scratch every time, then they would get no where with anything. Sure, learning how polarizers work by looking at gears means you'll have a really good intuitive grasp of polarizers, but no matter what you'll only be able to do simple systems. Once you have 4+ optical elements, any physical model will be too big an cumbersome to use. You know what is intuitive? 2x2 rotation matrices in the complex plane. It may not SOUND intuitive at first, but ANY 3D rotation can be modeled this way as long as you build up an intuition for how it works. It may take more effort, but you'll be able to have a system with 10+ elements and all you need to do is multiply ten 2x2 matrices together which anyone should be able to do. Honestly, nothing about this demo was novel or interesting other than his excitement to teach.
Love how passionate he is about this! At a push, I get about the same when talking about either real time rendering or optimization if you get a couple of beers down me.
Just a comment on finding the hand of circular polarized light.. Pick up a circular polarizer of a known polarization such as a RH polarizer. When viewing another source of light light of the same polarization will pass through. A TV showing a RH polarization will pass through a RH lens or filter. If there is a reflection such as using a projector onto a screen, the polarization flips when reflected, so a projector projecting LH polarization will light the screen that is viewed with a RH filter. Hope this helps. Why this works is when light is reflected, the E field induces a current into the reflector which reflects the wave with the E field flipped but the H field the same. In vertical or horizontal, it remains vertical or horizontal, but the polarity shift of the e field reverses direction as the relation between E and H in the wave is preserved. In circular polarization, the E field is flipped and the h field is preserved, again with a 180 reversal of the E field, in circular polarization, the wave is again reflected, but now with the E and H fields shifted 180 degrees making a RH into a LH and vise versa. Hope this helps. Pick up a RH circular polarizer and mark it as a reference for your work with light. My optics kit includes a linear polarizer with orientation marked (actually a camera filter for 36mm film) and a reference RH polarizer. Flipping the polarizer over does not change the hand, just the same as turning threaded rod end for end does not change a RH thread into a LH thread. Only a mirror image makes that change.
Agreed... I want my donation to go towards Gav's purchase of a new screen protector for his tablet. I'm thinking he's had that tablet since new and it's just the thin film across the screen to stop smudge marks at manufacture and should be removed.
"First principles" is the ONLY way to go because it is often the most direct connection between theory and experiment. I did some experiments with circularly polarized RF by slicing a parabolic dish from center to edge, then separating the outer edges front-to-back. Even without the math, just by varying the TX frequency and the edge separation I could get circular polarized transmissions over 10 km.
This is very cool... reminds me of the "slide rule" days where specific formulas were made into physical slide rule calculators... Man was put on the moon with slide rules, after all. This seems like a natural evolution of that simple yet powerful technology, as this is a 3d slide rule for polarized light. Awesome video... thanks for sharing it!
To learn some of the basics, a much longer wavelength in radio frequencies can be seen in the physical orientation of the electrical components. A dipole as a driven element makes a linear polarization matching the orientation of the antenna. vertical for vertical and horizontal for horizontal. If multiple stacked antennas are uses such as a Yagi antenna, and between elements there is a 90 degree twist that continues down the antenna, the direction of the twist produces a right hand or left hand circular polarization. I still do not have antenna model equivilants for 1/4 and 1/2 wave plates. Hoping to find them someday. On your demo table of objects, the addition of a simple first surface mirror often surprises those new to polarized light. A horizontal or vertical polarization will reflect just fine and you can see yourself through the polarizer. However if you use a circular polarizer of either hand, the reflection of the polarizer will always be black, even on the 3D shutter polarizer. Try it. This is because circular polarization when reflected off a mirror swaps the hand of the polarization so the returned light is always the wrong polarization to return through the polarizer. This technique is used in microwave transmission with a device called a circulator to divert reflected RF away from returning to the transmitter. Learning RF and antennas helped me understand polarized light as the same properties apply to radio with components large enough to see and hold the elements. Radio and light are the same but at different frequencies and wavelengths.
Dave, did you notice that the video in the end card thingies completely cover the links you've put in the end of the video? OK, they don't completely cover it, but enough so that they are not useful any more. Why do video creators do that? It makes no sense... (And it's a peeve I've had with many videos, ever since the RUclips end cards exist)...
Try water jet cutting your acrylic, this should reduce the heat when cutting. We do this when cutting lenses for our cameras. Which require being optically clear
I'm starting to understand a bit of this, but those are great visualisations of what's happening with different kinds of polarized light. Still have to read myself in....
Gonna be honest, this made it a bit more confusing for me. But, I absolutely love how passionate that guy is. He reminds me of some of the folks on Numberphile when they get to talking about primes 😁
a fun experiment for those interested -if you take TWO linear polarizing filters from your photo kit , cross them ninety degrees - and put some stretched cellophane between them - you can change the polarization of the light hitting the cellophane - and it will actually change that angle according to the stress in the cellophane making a wildly coloured pattern ... this is also how manufacturers etc would use polarized light to determine structural stresses before finite element analysis came along
With a camera that can shoot 120 pictures per second, plus electronically controlled linear and circular polarizing filters, and something like an Arduino, you might be able to get 30 fps video with polarization data per pixel (would need some post-processing to interpret the data, and the camera needs to have some way to have each frame be triggered electronically to ensure things are in sync). With an even faster camera, you could have a mechanical linear filter rotating at something like 15 rotations per second (if my math is right), and have either a rotation encoder, or actually have some sort of light source at the corner of the camera's field of view with a static linear filter between it and the camera, and use the brightness oscillations there to figure out the position of the rotating filter. For circular polarization it is more complicated; you won't be able to have the continuous changes like with the linear filter mechanically, at least not with a simple setup like this; but you can still have it rotating at 30 rotations per second on an axis orthogonal to the camera view axis; you would waste a lot of the frames while the filter is in the in-between orientations, but you'll at least get right and left-handed polarization every thirtieth of a second (and you can tell one handedness from the other with similar statically filtered light rig like from the linear setup. Temporal moire patterns might introduce some complications though; will depend on the exact setup you got; also, things could get a little messy with a rolling shutter camera.
After a zillion pictures, diagram, videos, Wikipedia and everything else that did nothing, I finally understood circular polarization - and holy crap, on eevblog, of all places...
Is there a good place to start with understanding polarized light? I'm very interesting in the subject but everyone always seems to start in the middle rather than the beginning.
I started with antenna theory as light and radio are simply different frequencies and wavelengths. The electric components as antenna elements on yagi antennas are very easy to see. Vertical, horizontal and circular of both polarizations are commonly used. Google yagi antenna and circular polarized directional antenna. For circular yagi antennas they have vertical and horizontal elements. Both the vertical and horizontal are fed with a relationship so one signal is following the other 1/4 wave behind it with a RH or LH orientation resulting in circular polarization.
For whomever needs a reminder of the basics: www.khanacademy.org/test-prep/mcat/physical-processes/light-and-electromagnetic-radiation-questions/v/polarization-of-light-linear-and-circular
Very interesting! Keep us updated on the project. I would love to see that camera in action. Are there any instruments today that can do what he aims to do with this special camera? I have a Lytro lightfield camera, and that technology is also very interesting. As I have understand the technology in the Lytro camera: there is a ton of pixels and there are a small micro lens in front of each pixel that senses both intensity of rgb light, but also direction the beam of light is coming from. So one pixel is seeing light from one special angle and the next pixel is another angle. Maybe something like that would work in this? Have a ton of pixels and a polarised filter in front of each pixel. Where there where different sets of filter around the complete image.... (hope that made sense)
Sugar cane is definitely sucrose - though it will in fact be d-sucrose in plants and l-sucrose if properly synthesized. Dextrose is a synonym for d-glucose, typically as blood sugar.
So he managed to construct physically, a concept which previously could only be described mathematically through advanced calculus. Brilliant! I would love to know what novel insights he has imagined about light, and the path he took to get there.
This is important for kiosk. There was a place I used to work that built these. With my sunglasses on, I could not see the screen of the kiosk. Think about a car display that you can't wear sunglasses with....
As an absolute polarization source, couldn't you also use solutions of optically active substances, since they are known to rotate a plane of polarization in one direction or the other? Besides dextrose there are organic compounds that you can buy in pure L- and D- forms. In order for a polarization filter to transmit the maximum intensity, it would have to be oriented in the same direction to the same degree as the light rotated by the solution. If you make solutions of the same concentrations (or large crystals) of L- and D- forms, your filters would need to be rotated to the same degree of rotation but in opposite senses (CW vs. CCW.) I haven't worked it out exactly, but perhaps this would be a way to calibrate your instruments without the aid of beetles, like the end of the movies, "Absolutely no beetles were harmed in any way during the making of this experiment."
The wave itself can be polarized and there are no filters because they would be huge/ impractical to build (also no reason, maybe in astronomy?). It's much more practical to build an antenna set up to pick up a specific polarization, rather than to filter it with a 2-mile long fence.
@12:00 "...so that it's much smaller than the wavelength of light"... No, single mode fiber has a core larger than the wavelength of light. 9 µm cores are typical while the light is typically 1.5 µm.
This sounds a lot like ray tracing that has been done for some time (and only just recently in real time) as a concept for graphics output on pc's. Only hes doing it somewhat backwards in that he wants to see the data on a per pixel level as generated by a camera, and how it is polarized in that single instance. Snap picture from two angles to get a 3d representation, with 2 different filters. Build the model in 3d with polarizing data attached and apply color maps in the same way they color map images out of an electron microscope, it might be interesting to include IR and UV data as well. I dont understand the math behind this, and im ok with that. But other than the " I just want to see beyond what my brain tells me i can see" what would the application for this tech be?
One of your most polarising videos Dave. Love his use of physical models. Achieving what seems to be the equivalent of a Lytro camera for polarised light would open up a new dimension of image analysis and processing capabilities. Let alone applications in RF, astronomy, ... Thank you.
D-Glucose = Dextrose. The naturally occurring "right-handed" form. L-Glucose is the left-handed version created synthetically and doesn't occur naturally.
Stop, plan, script, cross referance, get checked and proven and dude you should be on TV! This would make an excelent BBCFour tv science program if it was polished up.
Hehehe and how about a polarization filter for your Tegano microscope? So we wont see all the reflections on our screens as most of the things on a PSB is reflective.
Look through my grubby holes! Ya might be able to see ghosts and UFOs? I have some old active 3d glasses, would I just need to rotate one of them 180/90 degrees or something?
Could you not just have a global polarizer over the whole camera sensor, then rapidly take multiple photos while changing the polarization? (by either rotating the polarizer, or changing it electrically via an LCD shutter.) Or, have I also misunderstood this video, and that's what he's basically looking to do anyway? I'm just assuming he's not going to attempt to capture ALL of the polarization info for each PIXEL in a single snapshot using a single camera sensor. I can't even imagine how that would work, but it will be awesome to see how he eventually tackles the problem. I think I need to re-watch this when I'm fully awake. lol
I used to work in a few telecoms / fibre optics factories, and he's right about how they make beam splitters. lol I was surprised as well when I first saw how they make them. They literally just merge two fibres together while heating with some gas jets. There are two light meters hooked up to the fibres, and they just switch off the heaters just before the balance of light is 50% for each fibre. They also had to measure the PDL (Polarisation-Dependant Loss) for some splitters, though, to maintain that value below a certain level. Occasionally, if a device was a very marginal fail on the test set, we used to just twist the fibres very slightly, until it passed the test. lol
Oh, I think I see now. He wants to capture ALL polarization rotations with the camera, not just on-axis with the camera sensor. I really want to see how those photos (plus polarization info) would look like when displayed as a kind of 3D graph. We might even end up seeing a Blade Runner style camera that can do the "zoom and enhance" thing, so it can see around corners. lol
I'm really interested to see where this goes. It could be a new style of "light field" camera, but capturing far more than a normal one. Should be possible to combine it with "full range" IR / UV cameras, too. I'm not too sure of it's practical uses yet, but maybe it will prove the existence of ghosts or something? lol
I would imagine one of its main uses would be so a photographer could choose which parts of the image they wanted the reflections and highlights on. It's no doubt been done before just by taking a few shots of the same scene, but rotating the filter each time. That would only capture the on-axis stuff though. Gav (in the vid) will hopefully be able to capture far more information. It might even be useful for analysing materials and chemicals at a distance, like in space exploration perhaps.
would it be possible to create a camera that can convert the image to normals? like this: i.imgur.com/YjCSmzh.jpg (this image represents surface direction) that would be really usefull for tweaking lighting in post production
All this scorched wood reminds me somehow of Auschwitz.... However, if you have never heard of polarisation before this video and you now fully understand it, after looking at these models here, please leave a comment.
My nickname for multimode fiber is wrongmode. There is no advantage to multimode other than the optics used to be cheaper. If you are doing a network, do yourself a favour and go with singlemode.
![Megan Thee Stallion - Mamushi (Remix) [feat. TWICE] [Official Audio]](http://i.ytimg.com/vi/5c0_u9PsrsQ/mqdefault.jpg)
Oh right yes it all makes sense now.
Yeah I got no idea.
Technically, I understand more. But I am all the more certain that I don't really understand.
Awesome! Great to see someone so passionate about physics! Fascinating to listen to!
you get the feeling he would be HORRIBLE teacher though - kind of all over the place ADHD style
Man dropped a large portion of science.
@@philiprowney I have a basic understanding about some of the things he was talking about, but struggled to keep up. I think an interesting follow up video could be eevblog (dave) giving a slowed down explanation about some of the points gav made.
lot of pre-requisites needed to understand this fully.
Wood and aluminium and steel bolts?
e.g. a full understanding of polarised light
The trouble is like he said, we don't see polarisation... so we don't really understand it well. So you need to understand the requisites, unfortunately
great video. I'd also like to add that I appreciate the couple extra seconds at the end of each video, so I can pause it to like or comment before my playlist continues. I wish more people did that.
I could listen to this guy all day, what a brilliant mind.
great video, thanks for saying yes to all his "do you want to know about.." questions.
love this guys enthusiasm
LOL, hold on and let me get my beetle calibrator.
Characterized standard reference beetle
+
I'd say you need at least a Sgt.Pepper's calibrator for that.
@@thekaiser4333 Lucy in the sky with diamonds.
fyi, the abbreviations:
......................... Polarized
A = Anti-diagonal
D = Diagonal
H = Horizontal
V = Vertical
R = Right-hand circularly
L = Left-hand circularly
Myself, I didn't know what the A was there for
Very Interesting video. You could tell Gav really loves this stuff. :)
That is fascinating. More of this. Esoteric, yes.. but i'm glad someone is doing it. Amazing how much we see but don't see.
It's not really _that_ esoteric for anyone who has owned a halfway decent SLR & taken a photography class knows that one of the best filters you can add to your camera is a circularly polarized filter. You can rotate it and dial in or out how much effect you get.
But, yes, it's great content and I'm sure they'll be some cool use for it eventually. I wouldn't mind seeing a Part II to this one. I didn't know about the other types of polarized light even existing until this video. Good Job Dave!
This guy gave me secondhand passion about quantum phenomena just watching him.
Truly amazing stuff! Can't wait to see the images from your camera... Your models are astonishing too - as a chemist working with optical molecules I never *fully* understood these relationships - would have loved to have these as tools! Good explanation regarding sugars too - it's worth noting that we're referencing a dextrose, or glucose, monosaccaride when referring to dextro and levorotatory properties. Sugar, a sucrose fructose disaccaride, or indeed any polysaccaride, will of course also display rotation characteristics as a function of their combined monosaccarides.
Your guest may be interested in Sony's IMX250MZR camera sensor with polarizer filter array over pixels instead of color filter array. There are machine vision camera products shipping with this sensor already.
That came out this year, still very new. And it's a single package that is the same as 4 cameras with 4 filters -- or what the DolPi project did with multiple exposures through different filters; better performance/cost but the learning was done by tinkering here
Sure, learning by tinkering is better, but only up to a certain point. There is a reason we've come so far technologically and it's because we have access to all the information that was written down before our time. If every human had to start everything over from scratch every time, then they would get no where with anything. Sure, learning how polarizers work by looking at gears means you'll have a really good intuitive grasp of polarizers, but no matter what you'll only be able to do simple systems. Once you have 4+ optical elements, any physical model will be too big an cumbersome to use. You know what is intuitive? 2x2 rotation matrices in the complex plane. It may not SOUND intuitive at first, but ANY 3D rotation can be modeled this way as long as you build up an intuition for how it works. It may take more effort, but you'll be able to have a system with 10+ elements and all you need to do is multiply ten 2x2 matrices together which anyone should be able to do. Honestly, nothing about this demo was novel or interesting other than his excitement to teach.
This has really inspired me to learn about polarized light. I'm not going to, but I am inspired!
Love how passionate he is about this! At a push, I get about the same when talking about either real time rendering or optimization if you get a couple of beers down me.
Just a comment on finding the hand of circular polarized light.. Pick up a circular polarizer of a known polarization such as a RH polarizer. When viewing another source of light light of the same polarization will pass through. A TV showing a RH polarization will pass through a RH lens or filter. If there is a reflection such as using a projector onto a screen, the polarization flips when reflected, so a projector projecting LH polarization will light the screen that is viewed with a RH filter. Hope this helps. Why this works is when light is reflected, the E field induces a current into the reflector which reflects the wave with the E field flipped but the H field the same. In vertical or horizontal, it remains vertical or horizontal, but the polarity shift of the e field reverses direction as the relation between E and H in the wave is preserved. In circular polarization, the E field is flipped and the h field is preserved, again with a 180 reversal of the E field, in circular polarization, the wave is again reflected, but now with the E and H fields shifted 180 degrees making a RH into a LH and vise versa. Hope this helps.
Pick up a RH circular polarizer and mark it as a reference for your work with light. My optics kit includes a linear polarizer with orientation marked (actually a camera filter for 36mm film) and a reference RH polarizer. Flipping the polarizer over does not change the hand, just the same as turning threaded rod end for end does not change a RH thread into a LH thread. Only a mirror image makes that change.
That screen protector is an atrocity
Agreed... I want my donation to go towards Gav's purchase of a new screen protector for his tablet. I'm thinking he's had that tablet since new and it's just the thin film across the screen to stop smudge marks at manufacture and should be removed.
I would rather have a broken screen ;)
"First principles" is the ONLY way to go because it is often the most direct connection between theory and experiment.
I did some experiments with circularly polarized RF by slicing a parabolic dish from center to edge, then separating the outer edges front-to-back. Even without the math, just by varying the TX frequency and the edge separation I could get circular polarized transmissions over 10 km.
This is very cool... reminds me of the "slide rule" days where specific formulas were made into physical slide rule calculators... Man was put on the moon with slide rules, after all. This seems like a natural evolution of that simple yet powerful technology, as this is a 3d slide rule for polarized light. Awesome video... thanks for sharing it!
Really fantastic! Thanks for bringing this to us.
This guy should collaborate with Matthias Wandel to make super awesome high quality versions of all those contraptions!
Or @tesla500 who has an interest in optics.
To learn some of the basics, a much longer wavelength in radio frequencies can be seen in the physical orientation of the electrical components. A dipole as a driven element makes a linear polarization matching the orientation of the antenna. vertical for vertical and horizontal for horizontal. If multiple stacked antennas are uses such as a Yagi antenna, and between elements there is a 90 degree twist that continues down the antenna, the direction of the twist produces a right hand or left hand circular polarization.
I still do not have antenna model equivilants for 1/4 and 1/2 wave plates. Hoping to find them someday.
On your demo table of objects, the addition of a simple first surface mirror often surprises those new to polarized light. A horizontal or vertical polarization will reflect just fine and you can see yourself through the polarizer. However if you use a circular polarizer of either hand, the reflection of the polarizer will always be black, even on the 3D shutter polarizer. Try it. This is because circular polarization when reflected off a mirror swaps the hand of the polarization so the returned light is always the wrong polarization to return through the polarizer. This technique is used in microwave transmission with a device called a circulator to divert reflected RF away from returning to the transmitter.
Learning RF and antennas helped me understand polarized light as the same properties apply to radio with components large enough to see and hold the elements. Radio and light are the same but at different frequencies and wavelengths.
That's an interesting idea to make the camera sensor smart to polarization info!
Dave, did you notice that the video in the end card thingies completely cover the links you've put in the end of the video? OK, they don't completely cover it, but enough so that they are not useful any more. Why do video creators do that? It makes no sense... (And it's a peeve I've had with many videos, ever since the RUclips end cards exist)...
+1
No cards for me...
This showed up on my phone as "How to understand Polari" which is quite another thing!
Good Guest. His website is very informative.
Try water jet cutting your acrylic, this should reduce the heat when cutting. We do this when cutting lenses for our cameras. Which require being optically clear
I'm starting to understand a bit of this, but those are great visualisations of what's happening with different kinds of polarized light. Still have to read myself in....
Gonna be honest, this made it a bit more confusing for me. But, I absolutely love how passionate that guy is. He reminds me of some of the folks on Numberphile when they get to talking about primes 😁
Polarised light is also extremely useful in the fields of photography and microscopy, which are both interests of mine.
a LOT of this can also be applied to antenna theorem and how polarization of radio waves can be applied.
a fun experiment for those interested -if you take TWO linear polarizing filters from your photo kit , cross them ninety degrees - and put some stretched cellophane between them - you can change the polarization of the light hitting the cellophane - and it will actually change that angle according to the stress in the cellophane making a wildly coloured pattern ... this is also how manufacturers etc would use polarized light to determine structural stresses before finite element analysis came along
With a camera that can shoot 120 pictures per second, plus electronically controlled linear and circular polarizing filters, and something like an Arduino, you might be able to get 30 fps video with polarization data per pixel (would need some post-processing to interpret the data, and the camera needs to have some way to have each frame be triggered electronically to ensure things are in sync).
With an even faster camera, you could have a mechanical linear filter rotating at something like 15 rotations per second (if my math is right), and have either a rotation encoder, or actually have some sort of light source at the corner of the camera's field of view with a static linear filter between it and the camera, and use the brightness oscillations there to figure out the position of the rotating filter. For circular polarization it is more complicated; you won't be able to have the continuous changes like with the linear filter mechanically, at least not with a simple setup like this; but you can still have it rotating at 30 rotations per second on an axis orthogonal to the camera view axis; you would waste a lot of the frames while the filter is in the in-between orientations, but you'll at least get right and left-handed polarization every thirtieth of a second (and you can tell one handedness from the other with similar statically filtered light rig like from the linear setup. Temporal moire patterns might introduce some complications though; will depend on the exact setup you got; also, things could get a little messy with a rolling shutter camera.
After a zillion pictures, diagram, videos, Wikipedia and everything else that did nothing, I finally understood circular polarization - and holy crap, on eevblog, of all places...
Try this:
Polarization of Light: circularly polarized, linearly polarized, unpolarized light.
by Eugene Khutoryansky
ruclips.net/video/8YkfEft4p-w/видео.html
Very interesting. Too funny that one on the hardest parts is knowing left from right, haha.
Great interview partner!
Is there a good place to start with understanding polarized light? I'm very interesting in the subject but everyone always seems to start in the middle rather than the beginning.
www.feynmanlectures.caltech.edu/I_33.html
exactly, this was hopeless lol
and so is that
Polarization of Light: circularly polarized, linearly polarized, unpolarized light.
by Eugene Khutoryansky
ruclips.net/video/8YkfEft4p-w/видео.html
I started with antenna theory as light and radio are simply different frequencies and wavelengths. The electric components as antenna elements on yagi antennas are very easy to see. Vertical, horizontal and circular of both polarizations are commonly used. Google yagi antenna and circular polarized directional antenna. For circular yagi antennas they have vertical and horizontal elements. Both the vertical and horizontal are fed with a relationship so one signal is following the other 1/4 wave behind it with a RH or LH orientation resulting in circular polarization.
I like to think that I’m fairly intelligent, however this video just blew my mind.
My thoughts exactly x)
Great video!
For whomever needs a reminder of the basics:
www.khanacademy.org/test-prep/mcat/physical-processes/light-and-electromagnetic-radiation-questions/v/polarization-of-light-linear-and-circular
Very interesting! Keep us updated on the project. I would love to see that camera in action. Are there any instruments today that can do what he aims to do with this special camera?
I have a Lytro lightfield camera, and that technology is also very interesting. As I have understand the technology in the Lytro camera: there is a ton of pixels and there are a small micro lens in front of each pixel that senses both intensity of rgb light, but also direction the beam of light is coming from. So one pixel is seeing light from one special angle and the next pixel is another angle. Maybe something like that would work in this? Have a ton of pixels and a polarised filter in front of each pixel. Where there where different sets of filter around the complete image.... (hope that made sense)
Great stuff!
Sugar cane is definitely sucrose - though it will in fact be d-sucrose in plants and l-sucrose if properly synthesized. Dextrose is a synonym for d-glucose, typically as blood sugar.
Close, synthetic glucose will be a mixture of L- and D-glucose, chemists call this a 'racemate' or recemic mixture.
Tell Gav to use a water jet cutter to cut the acrylic pieces he needs so he doesn't introduce any heat stress into them.
So he managed to construct physically, a concept which previously could only be described mathematically through advanced calculus. Brilliant!
I would love to know what novel insights he has imagined about light, and the path he took to get there.
This is important for kiosk. There was a place I used to work that built these. With my sunglasses on, I could not see the screen of the kiosk. Think about a car display that you can't wear sunglasses with....
As an absolute polarization source, couldn't you also use solutions of optically active substances, since they are known to rotate a plane of polarization in one direction or the other? Besides dextrose there are organic compounds that you can buy in pure L- and D- forms. In order for a polarization filter to transmit the maximum intensity, it would have to be oriented in the same direction to the same degree as the light rotated by the solution. If you make solutions of the same concentrations (or large crystals) of L- and D- forms, your filters would need to be rotated to the same degree of rotation but in opposite senses (CW vs. CCW.) I haven't worked it out exactly, but perhaps this would be a way to calibrate your instruments without the aid of beetles, like the end of the movies, "Absolutely no beetles were harmed in any way during the making of this experiment."
Can be correlated to the properties of radio wave transmission.
Radio and visible light are both EM...
except there are no polarizing filters for radio waves ... hmmm interesting application for cryptography?
The wave itself can be polarized and there are no filters because they would be huge/ impractical to build (also no reason, maybe in astronomy?). It's much more practical to build an antenna set up to pick up a specific polarization, rather than to filter it with a 2-mile long fence.
Gav, you are the Best!
Now this hands on would have been a far better light 101 course!
Man that was awesome.
awesome! 3d models available?
19:32 Frenzal Rhomb. Great band.
This guy is........ just WOW!
the thingy could use a clean and a protective outer layer put in
@12:00 "...so that it's much smaller than the wavelength of light"...
No, single mode fiber has a core larger than the wavelength of light. 9 µm cores are typical while the light is typically 1.5 µm.
It's all relative.
This sounds a lot like ray tracing that has been done for some time (and only just recently in real time) as a concept for graphics output on pc's. Only hes doing it somewhat backwards in that he wants to see the data on a per pixel level as generated by a camera, and how it is polarized in that single instance. Snap picture from two angles to get a 3d representation, with 2 different filters. Build the model in 3d with polarizing data attached and apply color maps in the same way they color map images out of an electron microscope, it might be interesting to include IR and UV data as well.
I dont understand the math behind this, and im ok with that. But other than the " I just want to see beyond what my brain tells me i can see" what would the application for this tech be?
I'd guess another way of material analysis through visual data, may be a way of enhancing machine vision.
One of your most polarising videos Dave. Love his use of physical models. Achieving what seems to be the equivalent of a Lytro camera for polarised light would open up a new dimension of image analysis and processing capabilities. Let alone applications in RF, astronomy, ... Thank you.
D-Glucose = Dextrose. The naturally occurring "right-handed" form. L-Glucose is the left-handed version created synthetically and doesn't occur naturally.
Frenzels Rhomb! that made me LOL
Thanks for sharing👍😀
mechatronics guy? I STUDY THAT - your my kinda guy!
I didn't really understand it. This is good stuff for computer animations to visually what's happen...
Stop, plan, script, cross referance, get checked and proven and dude you should be on TV!
This would make an excelent BBCFour tv science program if it was polished up.
TV ? What's that, some pre-internet type of video service?
Too bad the passive glasses don't block all polarized light, or there's bleed from bright objects on my LG D2342P.
Awesome 👍👍👍👍
Very Nice guy.. but I cant transpose the demo to usefully visualise it in my own mind.
So as @Rob s said yeah still no idea.
OMG... How hard is it to wipe the f.ing finger gunk off the glass before you put it against the camera?
Haha yes was thinking the same. Guess nude virgins don't give a hoot ;)
AmbiDextrose ?
Does the glass ball actually polarize light or is it just there to hold the blue dot in place?
It's just holds the dot and is a visual representation
You would call it a educational/training device to assist in the understanding the concept.
APPROVED
I didn't get that. Can you, please, repeat, just slowly? Thank you!
Hehehe and how about a polarization filter for your Tegano microscope? So we wont see all the reflections on our screens as most of the things on a PSB is reflective.
Tagarno*
Oh, is THAT what the L- in front of L-Dextrose means? Hmm, that would explain all the L-Arginine and L-Carnitine in my protein drinks...
My brains melted.
Both of them? :o
Look through my grubby holes!
Ya might be able to see ghosts and UFOs?
I have some old active 3d glasses, would I just need to rotate one of them 180/90 degrees or something?
I didn't know there was such a thing as annealing plastic. Most of this video made quite a whooshing sound. Not quite fundamentals friday material.
The 'Schlieren Effect' is often used to visualise the stresses in the plastic before and after the annealing process to ensure its success.
hope his eye glass lenses are cleaner than his prototype lenses
Could you not just have a global polarizer over the whole camera sensor, then rapidly take multiple photos while changing the polarization?
(by either rotating the polarizer, or changing it electrically via an LCD shutter.)
Or, have I also misunderstood this video, and that's what he's basically looking to do anyway?
I'm just assuming he's not going to attempt to capture ALL of the polarization info for each PIXEL in a single snapshot using a single camera sensor. I can't even imagine how that would work, but it will be awesome to see how he eventually tackles the problem.
I think I need to re-watch this when I'm fully awake. lol
I used to work in a few telecoms / fibre optics factories, and he's right about how they make beam splitters. lol
I was surprised as well when I first saw how they make them.
They literally just merge two fibres together while heating with some gas jets. There are two light meters hooked up to the fibres, and they just switch off the heaters just before the balance of light is 50% for each fibre.
They also had to measure the PDL (Polarisation-Dependant Loss) for some splitters, though, to maintain that value below a certain level.
Occasionally, if a device was a very marginal fail on the test set, we used to just twist the fibres very slightly, until it passed the test. lol
Oh, I think I see now. He wants to capture ALL polarization rotations with the camera, not just on-axis with the camera sensor.
I really want to see how those photos (plus polarization info) would look like when displayed as a kind of 3D graph.
We might even end up seeing a Blade Runner style camera that can do the "zoom and enhance" thing, so it can see around corners. lol
It would appear that the device would be quite analogue/mechanical to do this as there appears no way to perform this digitally, which makes sense.
I'm really interested to see where this goes.
It could be a new style of "light field" camera, but capturing far more than a normal one.
Should be possible to combine it with "full range" IR / UV cameras, too.
I'm not too sure of it's practical uses yet, but maybe it will prove the existence of ghosts or something? lol
I would imagine one of its main uses would be so a photographer could choose which parts of the image they wanted the reflections and highlights on.
It's no doubt been done before just by taking a few shots of the same scene, but rotating the filter each time.
That would only capture the on-axis stuff though. Gav (in the vid) will hopefully be able to capture far more information.
It might even be useful for analysing materials and chemicals at a distance, like in space exploration perhaps.
would it be possible to create a camera that can convert the image to normals? like this: i.imgur.com/YjCSmzh.jpg
(this image represents surface direction)
that would be really usefull for tweaking lighting in post production
Forget about calcite, how about Carbonite? What light waves were getting through to Han Solo?
5:38 Applied Science about polarization in olive oil:
ruclips.net/video/XhU-nNiAgtI/видео.html
Nice explanation.
what does it look like if you light a candle 🕯🤔
circular polarized light
This video just went chiral!
Why can he not water jet cut the acrylic? instead of laser cut.
the makerspace Gav & I both visit doesn't have that kind of hardware
It's minds like these that advance human tech and understanding.
Someone please give that guy a 3d printer
Yup, I still don't understand how this works :D, it's all magic to me lol.
What the flying qubit was this all about?!
the circle lens is dirty.
Need an update!!!
All this scorched wood reminds me somehow of Auschwitz....
However, if you have never heard of polarisation before this video and you now fully understand it, after looking at these models here,
please leave a comment.
Anisotropic filtering ..... ahhhh makes sense
Looooooove it!!!!!!!
But can it core a apple?
My nickname for multimode fiber is wrongmode. There is no advantage to multimode other than the optics used to be cheaper. If you are doing a network, do yourself a favour and go with singlemode.
This guy is very nifty!
Great... now I feel dumb.
The Iso-Beatles. The most boring yet awesome bandname in quite a while.