It's a valid observation. A lens that could somehow do that without moving at all would be pretty magical, and the headline plays on this to get your attention. The headline could have been "MIT Creates Zoomable Lens That Works Using Heat" which is still cool, but not as sensational.
By this definition of movement absolutely nothing would do anything. If there was electric current you could say, "but the electrons are moving in the material". It's like saying your stove moves when you cook.
By any reasonable definition without moving parts means without any macroscopic (mechanical) parts that move.
I can warrantee you compacted snow is ice. Just go to Greenland, Argentina or Switzerland and see a glacier by yourself. You see ice and bubbles(bubbles could grow and become caves and over time they go up).
Icebergs are called ICE- berg for a reason, not snow-bergs.
If you had a snow that is 1/10 the density of water, just 10 meters of snow means 1 atmosphere of pressure. That pressure compresses the snow, making 10 meters hold more water and more pressure.
There are places in the world with glaciers higher than three kilometers(1.8 miles).
I think that the point is that there is nothing that you could really "separate as a part", everything being fused into a single piece impossible to disassemble without destroying it.
To me this kind of sounds like turning a bug into a feature. And that's great. I would not doubt if they were having a problem with phase shift with temp and thought, "Hey, what if we did this intentionally?"
Usually engineers hate the electromagnetic phase shift that comes from temperature change, or worse, temp changed caused physical shifts in phase of the material. One notable example of this is the PTFE dielectric material for coaxial cables which has become notorious for the "teflon knee" in it's temperature vs phase plot.
[The] camera uses a liquid lens powered by a motor that uses precision manipulation on that packet of fluid to switch between a 3x telephoto zoom and a macro mode [..]
If I understand correctly, the lens in the Xiaomi Mi Mix Fold does require a mechanical movement to be adjusted (it's also clearly visible in the video), so I'm not sure what is the point.
It's a much more compact mechanical movement than a traditional focusing system, allowing them to use the same sensors for two different zoom levels on the phone. Right now this is otherwise being done by using multiple sensors and lenses instead.
I remember prior literature on liquid lenses used electric charges. It is possible the ones in the phones use mechanical movements to get around patents.
I think I also remember something like that. It might have been an interface between silicon oil and a saline solution that was deformed by applying an electric field.
You can change the zoom/focus by a lot more if the lens can be made to change shape, kind of like the eye. You would need to have a much greater degree of movement to replicate it with hard lenses.
You could also do things like use different patches of the sensor to focus different parts of the scene. Depending on how much the lens can morph, it could provide for bifocal functionality or limited fly eye.
This is essentially a zone plate reflector which has two states, and thus switchable focal points.
The images shown lead me to suspect this is a binary zone plate, which has a much narrower bandwidth over which it would be effective.
However, this is all prototypes, if they can indeed make a zone plate that can be addressed as pixels, with finer control over phase shift at each pixel, there are quite a few places where it would be quite useful, in spite of the narrower bandwidth.
That's incorrect, metalenses are not diffractive lenses. They continuisly change the local refractive index through subwavelength structures. There's a brief introduction and discussion about differences with diffractive lenses here: https://www.nature.com/articles/s41467-020-15972-9
It looks like the material is organized on a grid. Imagine a lense + algorithm that conforms to the depth map of the FOV. You could get super focus (there's probably more appropriate term) in a single shot.
No, they are describing a lens that can change the effective focus for different regions of the image, so that you can get multiple parts in focus at the same time.
There are no light field tricks here.
Always thought that camera lenses the way they are, are the already obsolete technology. I mean we can fit billions of transistors on a fingernail, but we need this mechanical contraption to zoom things? I think this invention is still not it, but I am glad the tech in that space is finally going somewhere. Don't get me wrong, I love lenses but it feels like using something from a last century, even though it was just made.
I love the idea of these electro-optic (or in this case electo-thermal) configurable lenses. and fourier optics in general.
What range of optical wavelengths did this lens operate well over, or could a similarly constructed system operate. My experience with electron beam exposed PMMA grating/lenses was that they were OK over the optical range, but did show noticeable dispersion, while for filtered (or laser) optics they worked extremely well to replace much thicker/heavier system solutions.
This was designed for the mid-IR (5.2um). I don’t recall its bandwidth but is was small on order of 100nm.
The dispersion of this material in the mid-IR is relatively flat.
There is active research on dispersion engineering via more complex geometry of the ‘meta-atoms’ to broaden the bandwidth for achromatic metalens optics.
Other research is actively looking to design materials that could have this phase change functionality in the visible wavelength range. All stable phase change materials to my knowledge strongly absorb in the visible range.
Thanks a lot for the quick response! I read enough to see it was designed for multi-micron, but was hoping it would still work down to near-IR. It will be hard to use this for depth imagers or standard CMOS at those longer wavelengths, but for true IR cameras it could be amazing.
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[ 3.5 ms ] story [ 107 ms ] threadSo it does move, just on a smaller scale.
come on guys, we all know what the title means
By any reasonable definition without moving parts means without any macroscopic (mechanical) parts that move.
Maybe "zoomable lens with no conventional moving parts", or "non-mechanical zooming" or solid-state zoom lens or...
https://en.wikipedia.org/wiki/Snow
Icebergs are called ICE- berg for a reason, not snow-bergs.
If you had a snow that is 1/10 the density of water, just 10 meters of snow means 1 atmosphere of pressure. That pressure compresses the snow, making 10 meters hold more water and more pressure.
There are places in the world with glaciers higher than three kilometers(1.8 miles).
https://en.wikipedia.org/wiki/Superheating#Occurrence_via_mi...
This is to put in perspective with a Zoom Lens where moving parts are designed to be assembled and disassembled: https://www.lensrentals.com/blog/2021/01/the-secret-of-the-b...
Also, a heated metal bar dilates and thus moves, not sure it is considered having "parts".
Usually engineers hate the electromagnetic phase shift that comes from temperature change, or worse, temp changed caused physical shifts in phase of the material. One notable example of this is the PTFE dielectric material for coaxial cables which has become notorious for the "teflon knee" in it's temperature vs phase plot.
The First Smartphone to Use a Liquid Lens is the Xiaomi Mi Mix Fold
https://petapixel.com/2021/03/30/the-first-smartphone-to-use...
Liquid Lens Features, Applications, and Technology
https://www.edmundoptics.com/knowledge-center/application-no...
If I understand correctly, the lens in the Xiaomi Mi Mix Fold does require a mechanical movement to be adjusted (it's also clearly visible in the video), so I'm not sure what is the point.
The glass is deformed rather than moved. The main selling points compactness and very fast change of focus.
The images shown lead me to suspect this is a binary zone plate, which has a much narrower bandwidth over which it would be effective.
However, this is all prototypes, if they can indeed make a zone plate that can be addressed as pixels, with finer control over phase shift at each pixel, there are quite a few places where it would be quite useful, in spite of the narrower bandwidth.
https://en.wikipedia.org/wiki/Zone_plate
It's cool tech, there was a company called Lytro that tried to commercialize them a while back.
Though metalens need to be heated, it's a very cool concept!
https://www.caltech.edu/about/news/ultra-thin-camera-creates...
Possibly faster, more reliable.
What range of optical wavelengths did this lens operate well over, or could a similarly constructed system operate. My experience with electron beam exposed PMMA grating/lenses was that they were OK over the optical range, but did show noticeable dispersion, while for filtered (or laser) optics they worked extremely well to replace much thicker/heavier system solutions.
https://www.usenix.org/system/files/raid20-man.pdf