Karl Guttag

For AR/VR, https://youtube.com/c/SadlyItsBradley is cringe, but he has solid supply chain info leaks about upcoming products and a surprisingly good understanding of the technology. Meanwhile, https://kguttag.com is by far the best place to learn about the many fundamental unsolved problems that are preventing the grand vision of metaverse AR glasses from being realized anytime soon, and the reality of what upcoming products will be like as they work around those problems in various ways.

For analysis of new AR/VR technology I highly recommend Karl Guttag's blog: https://www.kguttag.com/ He's an engineer that understands the limitations of physics, especially when it comes to optics and light. He is very good a parsing marketing hype vs reality. (He called BS on Magic Leap years before it launched.) His posts are exceptionally well researched and explained, even if you don't have a background in physics or optics. He recently did an analysis of the Apple Glass leaks. I expect he'll post his thoughts on this new technology from FB soon.

Wow, they burned billions. Karl Guttag has blogged about them for years, debunking their technology. Hi blog is a good read for all things in the AR/VR space https://www.kguttag.com/

AR -- headsets are too expensive but nowhere near good enough. See https://kguttag.com/ VR -- the hardware is fine for sedentary activities. if you want to get up and walk around the problems get big. tracking is one thing, but you have to make the whole environment safe (no tripping on couches, pets, etc.) I would love to rent out an old big box store and turn it into a "VR park" where people would play physically intense games like laser tag. You have to worry about people crashing into structural supports, taking hard falls wearing $3000 worth of gear, running past barriers you enforce with the VR system, etc. What holds up VR now is that the software is not that compelling. VR games aren't really better than regular video games. The best applications so far are "watch a movie in an imaginary movie theater", "use your computer in an environment with many virtual screens".

Vision Pro has been out for almost 2 years now, so I'm not surprised. It's also worth noting that the lenses and engineering decisions around the optics can have way more influence on perceived image quality than just the specs would imply. Here's just one discussion around the challenges and decisions made around optics: https://kguttag.com/2024/03/01/apple-vision-pros-optics-blurrier-lower… I'm actually more surprised that Apple's update to Vision Pro was just a CPU bump that failed to address the criticisms people had - namely weight, price, and content/lack of a killer app. The Vision Pro's M5 is roughly 4-7 times faster in Geek Bench than the Galaxy XR's Snapdragon XR2+ Gen 2 so it'll be interesting to see whether the Galaxy XR will be hindered in any way.

The author finally got his hand on a Vision Pro and made a follow up here: https://kguttag.com/2024/02/05/spreadsheet-breaks-the-apple-vision-pro…

Here you go! It's not great. https://kguttag.com/2024/02/05/spreadsheet-breaks-the-apple-vision-pro…

That's debatable - the Quest Pro has been roundly criticised for having passthrough that isn't good enough for many AR applications (e.g.: you can't read text through it and it has very poor temporal stability), while being marketed for those applications. If they can't do great passthrough at 1,500 dollars, it unlikely that they'll do good passthrough for 400. Hope to be proven wrong, as I'd love to use a headset for productivity. There's a good overview here - https://kguttag.com/2023/01/03/meta-quest-pro-part-1-unbelievably-bad-…

This guy had a pretty good series of posts on Magic Leap. They're not positive https://kguttag.com/?s=magic+leap EG "This blog has been reporting why from a technical perspective on the massive problems with Magic Leap since November 2016. At that point, Magic Leap had “only” raised about $1.4B. They were able to raise another $1.2+ billion since this blog started reporting on their hype. Magic Leap’s total VC raise of over $2.6B dwarfs the measly $700m raised by the infamous Theranos." https://kguttag.com/2020/05/03/magic-leap-starts-to-auger-in-with-3-7x…

The thing is - they don't really have much IP worth anything. They have filed a ton of patents for ridiculous stuff like that "wiggling" fiber idea (the fiber would need to reach ultrasonic speeds to get anywhere close to usable display). Also, according to this, all their patents are assigned to JP Chase as collateral: https://www.kguttag.com/2019/11/10/all-magic-leap-patents-have-apparen… They want to exit because their investors don't want to pour more money into that bottomless pit, with no prospects of profitability (not to mention that there are other vendors doing the same thing and better/cheaper). So hype things up, offload the worthless junk to some sucker and move to the Caribbean to enjoy the "profits" ...

Sorry about the slow reply, it’s a very reasonable question you’re asking. http://www.kguttag.com Let your fingers do the walking.

Haha ... or more than a million!! One thing I like about CES are the frank conversations with engineers. This year, I reached out to a few people. Had a very nice conversation with Karl Guttag (he has an optics blog http://www.kguttag.com/). I'm a newb in this area but had burning questions for a while .. he very patiently explained optics 101 and some of the implications. Very nice guy in person. I also spoke to/saw engineering demos at the TI booth in LVCC, AMD and ARM booths at the Venetian/Sands, NXP and Qualcomm at LVCC. They have some private demos that are by appt only but usually let you in if you ask politely. I just went up and said I would like to know more about X or Y. Is there an engineer who can help me? I also missed Kopin and Vuzix. Time was short and I could not find them :/

Another post from today, really laying out the math behind hi-res FSD being a bad joke. http://www.kguttag.com/2018/01/06/magic-leap-fiber-scanning-display-fs… Key point... Thus the fiber needs go 10.17 meters X 240/sec = 2,400 meters/sec. For reference, the speed of sound is a mere ~343 meters per second (varies with temp and air density) so the fiber has to average about 7 times the speed of sound and because it is accelerating and decelerating back to zero at each end, it has to have a peak velocity of greater than 14 times the speed of sound!!!!!

The "About" link on the upper left of the site's homepage goes here: https://kguttag.com/about-karl-guttag/ But I found his blog a couple years ago and have been reading it ever since. Karl follows VR/AR display tech obsessively, goes to all the shows/conferences and talks with all the companies - then does highly technical, in-depth write-ups of what's new and notable - which often includes his unvarnished opinions. His blog is read by basically everyone in the industry, so all the companies give him briefings and demos despite the fact he'll call it like he sees it. Which is why he's pretty much my go to source when any new VR/AR display tech gets announced. Even more valuable to me, he'll mention when companies are lagging or falling short of expectations and he'll even speculate about where things could (or should) go. His blog is basically like having a buddy who's an expert industry insider who'll tell you what he really thinks over a beer - which is pretty invaluable if you're someone who's interested and technical but doesn't follow this space that closely. That doesn't mean Karl's opinion is always correct but it is certainly well-informed and usually supported with technical data - although he did say this post was just a quick note that a video was leaked. He'll probably have a real post after it's announced and a deep dive once he gets his hands on one. Interesting fact: Karl's career was as a chip architect. He designed key parts of the the Texas Instruments…

Let's imagine you aspire to 1080p. AR glasses can more or less provide that as a 4 m screen at 2 m distance, with pov angles similar to a laptop screen. With head tracking, that can be a 1080p portal into a larger workspace. For 1:1 realistic motion, notice how far you have to move your head to point your nose at imaginary laptop screens above or to the side of your real one. Unrealistic motion[1] can reduce that, but I don't know if it's available off-the-shelf. VR headsets trade pixel density for FOV. An Apple Vision Pro has a PPD similar to AR glasses in the center, but that's ~halved by the time you reach the edge of a 4 m 1080p screen at ~30 deg from center[2]. That blur makes eye motion across the screen less available. Try using a laptop screen while keeping your nose pointed at your focus. Head motion gives you greater apparent resolution by temporal supersampling - someone else will have to weigh in with Vision Pro experience. Giant floating monitors may have been technically possible in non-glasses non-VR HMDs for a few years now. We're mostly limited by pixels-per-degree, and that by panel resolution, rather than optics. There have repeatedly been 2x or more higher res panels available in the sizes used in HMDs. But the HMD market is VR games, which wants large FOV for immersion, is cost sensitive, has optics limitations, and needs higher frame rates, which with GPU and bandwidth limitations (and eye tracking unavailable), makes resolution a "you couldn't use it…

Has anyone posted a deep dive yet on pinning down which exact waveguide design is being used and which exact projector (based on past papers, M&A activity, key hires, etc.)? I'm surprised Karl Guttag hasn't published anything yet about either Orion or Spectacles 24. https://kguttag.com/ His blog is normally the definitive source for reverse-engineering AR optics systems from public information. Maybe someone posted a deep dive on Reddit or something ? I'll post links here that could serve as a starting point: - The microLED display panel vendor is likely to be Plessey: https://www.uploadvr.com/facebook-plessey-microled-deal/ - The waveguides are likely being produced "directly" by a contract manufacturer working under the direction of Meta's in-house team, and reporting appears to confirm that Meta is procuring the raw materials directly: "The silicon carbide waveguides are also proving challenging to procure. The material can deliver a wider field of view than the glass waveguides used in current transparent AR headsets, but it is also incredibly expensive. Further, Ma's report explained that because the material is used in military radars and sensors, the US government imposes strict export controls on it. That means glasses using it will have to be assembled inside the US, significantly raising the production cost, despite most of the manufacturing and components coming from China and Taiwan." …

Paid PR piece, anyone? And still the writer is reaching so far they're going all the way around the world back into their own ass trying to praise this thing. <rant> I'm so fucking done with MagicLeap. Their head conman CEO, who is, absolutely and by all accounts, an absolutely fantastic showman and salesman, has taken so much money and so much hype that it's not going to end well. Pretty much EVERYONE who has tried the magic leap headset has basically said 'meh'. It blocks around 85% of the incoming light [1], for fuck's sake. That's the first of a very long list of 'meh'. Why am I so pissed off about this? Because it's going to crash the AR industry (already on its knees because of an overhyped VR industry) and set it back years. Already, and for years now, no one wants to invest in an AR hardware startup because "how could you possibly beat Magic Leap? Fuck those guys. And the dumb investors who let themselves be fondled into throwing billions? Shame on you! </rant> The same thing happened to lightfield imaging with Lytro (who took "only" a few hundred million in comparison). Lightfield imaging has been stagnant ever since they took too much money and sucked all the oxygen out of an entire industry. [1] https://www.kguttag.com/2018/09/26/magic-leap-review-part-1-the-terrib…

The optics for the avp are noticably softer than quest3 https://kguttag.com/2024/03/01/apple-vision-pros-optics-blurrier-lower… so the screen resolution might be higher, the effective resolution is not so much. The quest feels sharper for a lot of things. Apart from the rgb camera. Either way, for me, they are both too lower resolution for useful text work. I can see the pixels and the size of the font I want starts to fall below the effective reolution. I realise that this is not the case for a lot of people though

This reminds me of the original patents that Magic Leap had, which involved pumping light through a single optical fiber that was wiggled by piezoelectrics into a spiral to project light (https://kguttag.com/2018/01/06/magic-leap-fiber-scanning-display-fsd-t…

The Magic Leap was around 30 pixels per degree when it was still sold. https://kguttag.com/2022/01/31/magic-leap-2-at-spie-ar-vr-mr-2022/

The author received both devices from tear downs by iFixIt and was able to see the image without the lens (without the blurring) as explained in Part 1. Though it seems the AVP tends to do some post processing no matter how they image is displayed > I see different processing and artifacts happening when natively rendering on the AVP (such as when running Excel), displaying a saved bitmap from a file on the AVP, displaying a bitmap image on a web page, and mirroring the content of a MacBook. With each test image, seeing how it will display differently with each display mode is an adventure. https://kguttag.com/2024/02/16/apple-vision-pros-avp-image-quality-iss…

Out of curiosity, did you look at the About section of the website that the article is from? https://kguttag.com/about-karl-guttag/

While I haven't verified it, that's Microsoft's own claim so they will have their reasons for citing that number so I won't make a claim one way or the other, but have provided a link to the dispute below(1). Simula is not a shipping product, which to be fair means I should be comparing it with any announced but not yet shipping product, and probably not with products that were announced 4 years ago. (1) https://kguttag.com/2020/07/08/hololens-2-display-evaluation-part-2-co…

See also Karl Guttag's review at SPIE [0] (in particular read the "Conclusions" section) and HN discussion from Feb 2022 [1] [0] https://kguttag.com/2022/01/31/magic-leap-2-at-spie-ar-vr-mr-2022/ [1] https://news.ycombinator.com/item?id=30170924

That doesn't match up with what people who know about optics think is possible: https://kguttag.com/2021/10/28/magic-leap-2-pt-3-soft-edge-occlusion-a…

From my perspective watching their marketing, Magic Leap did over-hype / under-define the product's utility. Their original use-case appeared to be everything and their tech predictably missed it. Contrast to the tech https://www.youtube.com/watch?v=t4f8ZZv_j_c&t=3390s that Karl G appears to give kudos to on his site https://kguttag.com/2021/11/19/awe-2021-part-1-tilt-5-was-magical/. It has a rough-edge which is overtly used as a product attribute: the "game board" is required ... detail: it is made of the common micro-spherical retro-reflective (road-sign) surface, leading to a relatively low $400 barrier-to-entry. These trade-offs appear to be smart. Q: How did Tilt5 take the "smart" path and Magic Leap the "way of pain?" (whimsy: https://www.youtube.com/watch?v=QCNEzFpIrP8)

???? the hype was around their fiber scanning display patents, they were showing investors a totally new technology that projects images into your eyeballs. There are numerous articles describing the patented pie-in-the-sky vs the state-of-the-art, just one example here: [0] > They don’t even have an decent brightness control of the pixels and didn’t even attempt to show color reproduction (requiring extremely precise laser control). Yes the images are old, but there are a series of extremely hard problems outlined above that are likely not solvable which is likely why we have not seen any better pictures of an FSD from ANYONE (ML or others) in the last 7 years. Magic Leap was unable to improve and miniaturize this technology - its a dead end - so they ended up using the same tech as everyone else [0] https://kguttag.com/2016/11/28/magic-leap-no-fiber-scan-display-fsd/

In general, I find Karl Guttag’s analysis far superior: https://www.kguttag.com/2020/05/20/analyzing-front-page-techs-apple-gl…

This article does a good job: https://www.kguttag.com/2019/12/18/hololens-2-not-a-pretty-picture/ Digilens is a company that's been around for 15 years doing all kinds of eye wear stuff.

Fiber scan display in hi res would’ve required moving at 14× speed of sound: https://www.kguttag.com/2018/01/06/magic-leap-fiber-scanning-display-f…