8 ms·
Zoomable lens without any moving parts
- tryonenow 6y agoIt 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.
- tfolbrecht 6y agoWhat you're describing is a light field camera. It's cool tech, there was a company called Lytro that tried to commercialize them a while back.
- namibj 6y agoNo, 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.
- smcleod 6y agohttps://web.archive.org/web/20210403031009/https://www.extremetech.com/extreme/320211-mit-creates-zoomable-metalens-without-any-moving-parts https://web.archive.org/web/20210403031009/https://www.extre...
- fortran77 6y ago> When heated, the atomic structure of the material rearranges So it does move, just on a smaller scale.
- whymauri 6y agobefore even opening the thread, i knew someone would make this comment. come on guys, we all know what the title means
- jamesgreenleaf 6y agoIt'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.
- craftinator 6y agoOr better yet, "MIT Creates Zoomable Lens That Works by Moving More or Less".
- cycomanic 6y agoBy 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.
- foota 6y agoWell, I actually thought this was going to be about phased array optics, so I guess there is some distinction here.
- cycomanic 6y agoThis is quite close to phased array optics actually.
- m463 6y agoI think on sites like HN - even with non-controversial subjects - you have to say "improbable" instead of "impossible" and stay away from absolutes. Maybe "zoomable lens with no conventional moving parts", or "non-mechanical zooming" or solid-state zoom lens or...
- zackbloom 6y agoAtomic structure shifts are not conventionally considered ‘moving’. Most people wouldn’t call water turning to ice a ‘movement’.
- scollet 6y agoNot until the glaciers show up.
- gpuhacker 6y agoA glacier is compacted snow, not ice
- hn8788 6y agoSnow is ice.
- kortilla 6y ago> Snow comprises individual ice crystals https://en.wikipedia.org/wiki/Snow https://en.wikipedia.org/wiki/Snow
- bumbada 6y agoI 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).
- klyrs 6y agoJust wait til you hear about supersolids
- m463 6y ago
- kelsolaar 6y agoI 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. 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-broken-element-a-canon-rf-100-500mm-f4-7-7-1-teardown/ 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".
- intrasight 6y agoIf the phase change causes the whole lens to stretch or shrink, then it would fit my definition of "move"
- mrdrrobots 6y agoDefine ‘move’. All matter ‘moves’ on some scale even at absolute zero temperature.
- superkuh 6y agoTo 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.
- touisteur 6y agoHey, phase shift is great for radars and radar-like processing. If you can control or calibrate it it somehow, you're gold.
- mrdrrobots 6y agoWe actually engineered the material specifically for its optical/IR behavior. See: https://www.nature.com/articles/s41467-019-12196-4 https://www.nature.com/articles/s41467-019-12196-4
- notjtrig 6y agoInteresting, looks like the last big lens tech, liquid lenes are finally here. 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-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-notes/imaging/introduction-to-liquid-lenses/ https://www.edmundoptics.com/knowledge-center/application-no...
- bnegreve 6y ago[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.
- simcop2387 6y agoIt'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.
- ampdepolymerase 6y agoI remember prior literature on liquid lenses used electric charges. It is possible the ones in the phones use mechanical movements to get around patents.
- _Microft 6y agoI 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.
- perryizgr8 6y ago
- mikewarot 6y agoThis 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. https://en.wikipedia.org/wiki/Zone_plate https://en.wikipedia.org/wiki/Zone_plate
- cycomanic 6y agoThat'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 https://www.nature.com/articles/s41467-020-15972-9
- amelius 6y agoWhy is "meta" in the name?
- jasonwatkinspdx 6y agoIt's a general category of assemblies / structures that mimic a material with unusual or even impossible properties: https://en.wikipedia.org/wiki/Metamaterial https://en.wikipedia.org/wiki/Metamaterial
- mrdrrobots 6y agoCo-author here, Not a binary zone plate.
- mikewarot 6y agoHow wide of a bandwidth could this handle? Do you think it will be possible to cover the entire visible light spectrum some day?
- YY-EN40P 6y ago> It’s just a proof of concept right now, but it’s a very cool concept. Though metalens need to be heated, it's a very cool concept!
- intricatedetail 6y agoAlways 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.
- mkr-hn 6y agoLenses are like rockets in that way. The physics of light and space are unforgiving and hard to solve.
- tomkat0789 6y agoBah, Caltech can top that. Why bother with a lens? How about an optical phased array? :) https://www.caltech.edu/about/news/ultra-thin-camera-creates-images-without-lenses-78731 https://www.caltech.edu/about/news/ultra-thin-camera-creates...
- tambourine_man 6y agoI’d also wager on computation vs moving parts, even if those moving parts are microscopic. Possibly faster, more reliable.
- mrdrrobots 6y agoCo-author here: link to the journal article: https://www.nature.com/articles/s41467-021-21440-9 https://www.nature.com/articles/s41467-021-21440-9
- kurthr 6y agoI 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.
- mrdrrobots 6y agoThis 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.
- kurthr 6y agoThanks 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.
- ta1234567890 6y agoSo at what scale do we call movement movement? Because things are moving inside this lens, but at a molecular/atomic level.
- bradgranath 6y agoNo magic photon teleportation happening here: it moves. Just not with gears.
- moonplot 6y agoThis reduces ghost effects as well, of which was taken advantage by an attacker who eventually inject stop signs, for instance, into the imager: https://www.usenix.org/system/files/raid20-man.pdf https://www.usenix.org/system/files/raid20-man.pdf