Supercon: Alex Hornstein’s Adventures In Hacking The Lightfield

We are all familiar with the idea of a hologram, either from the monochromatic laser holographic images you’ll find on your bank card or from fictional depictions such as Princes Leia’s distress message from Star Wars. And we’ve probably read about how the laser holograms work with a split beam of coherent light recombined to fall upon a photographic plate. They require no special glasses or headsets and  possess both stereoscopic and spatial 3D rendering, in that you can view both the 3D Princess Leia and your bank’s logo or whatever is on your card as 3D objects from multiple angles. So we’re all familar with that holographic end product, but what we probably aren’t so familiar with is what they represent: the capture of a light field.

In his Hackaday Superconference talk, co-founder and CTO of holographic display startup Looking Glass Factory Alex Hornstein introduced us to the idea of the light field, and how its capture is key to  the understanding of the mechanics of a hologram.

Capturing the light field with a row of GoPro cameras.
Capturing the light field with a row of GoPro cameras.

His first point is an important one, he expands the definition of a hologram from its conventional form as one of those monochromatic laser-interference photographic images into any technology that captures a light field. This is, he concedes, a contentious barrier to overcome. To do that he first has to explain what a light field is.

When we take a 2D photograph, we capture all the rays of light that are incident upon something that is a good approximation to a single point, the lens of the camera involved. The scene before us has of course countless other rays that are incident upon other points or that are reflected from surfaces invisible from the single point position of the 2D camera. It is this complex array of light rays which makes up the light field of the image, and capturing it in its entirety is key to manipulating the result. This is true no matter the technology used to bring it to the viewer. A light field capture can be used to generate variable focus 2D images after the fact as is the case with the Lytro cameras, or it can be used to generate a hologram in the way that he describes.

One possible future use of the technology, a virtual holographic aquarium.
One possible future use of the technology, a virtual holographic aquarium.

The point of his talk is that complex sorcery isn’t required to capture a light field, something he demonstrates in front of the audience with a volunteer and a standard webcam on a sliding rail. Multiple 2D images are taken at different points, which can be combined to form a light field. The fact that not every component of the light field has been captured doesn’t matter as much as that there is enough to create the holographic image from the point of view of the display. And since he happens to be head honcho at a holographic display company he can show us the result. Looking Glass Factory’s display panel uses a lenticular lens to combine the multiple images into a hologram, and is probably one of the most inexpensive ways to practically display this type of image.

Since the arrival of the Lytro cameras a year or two ago the concept of a light field is one that has been in the air, but has more often been surrounded by an air of proprietary marketing woo. This talk breaks through that to deliver a clear explanation of the subject, and is a fascinating watch. Alex leaves us with news of some of the first light field derived video content being put online and with some decidedly science-fiction possible futures for the technology. Even if you aren’t planning to work in this field, you will almost certainly encounter it over the next few years.

Continue reading “Supercon: Alex Hornstein’s Adventures In Hacking The Lightfield”

Way to Go, Einstein; His Time Spent Being Wrong

When you hear someone say “Einstein”, what’s the first thing that pops into your head? Is it high IQ… genius… or maybe E=MC2? Do you picture his wild grey hair shooting in all directions as he peacefully folds the pages back from his favorite book?  You might even think of nuclear bombs, clocks and the Nobel Prize. It will come as a surprise to many that these accomplishments were a very small part of his life. Indeed, Einstein turned the world of classical physics upside down with his general theory of relativity. But he was only in his early twenties when he did so.

What about the rest of his life? Was Einstein a “one-hit-wonder”? What else did he put his remarkable mind to? Surely he tackled other dilemmas that plagued the scientific world during his moment in history. He was a genius after all… arguably one of the smartest people to have ever walked the earth. His very name has become synonymous with genius. He pulled the rug out from under Isaac Newton, whose theories had held the universe together for over 300 years. He talked about enigmatic concepts like space and time with an elegance that laid bare the beauty hidden within their simplicity. Statues have been made of him. His name and face are recognizable across the globe.

But when you hear someone say “Einstein”, do you think of a man who spent the better half of his life… being wrong?  You should.

Continue reading “Way to Go, Einstein; His Time Spent Being Wrong”

Eclipse 2017: Was Einstein Right?

While most people who make the trek to the path of totality for the Great American Eclipse next week will fix their gazes skyward as the heavenly spectacle unfolds, we suspect many will attempt to post a duck-face selfie with the eclipsed sun in the background. But at least one man will be feverishly tending to an experiment.

On a lonely hilltop in Wyoming, Dr. Don Bruns will be attempting to replicate a famous experiment. If he succeeds, not only will he have pulled off something that’s only been done twice before, he’ll provide yet more evidence that Einstein was right.

Continue reading “Eclipse 2017: Was Einstein Right?”

Wolfenstein in 600 Lines of Code

What’s more impressive, the fact that this Wolfenstein-like game is 600 lines of code, or that it’s written in AWK?

AWK is a language primarily used for text processing. But if you can write code the world bows to your wishes. [Fedor Kalugin] leverages the ability of a Linux terminal’s color options to draw his game. The 3D aspect is produced through ray-casting which generates a 2D image from 3D coordinates.

Trying out the game is extremely simple, install gawk, clone the repo, and play:

Continue reading “Wolfenstein in 600 Lines of Code”

Frankensteined Cordless Drill Lives Again

With tools, especially cordless tools, you’re going to pay now or pay later. On one hand, you can spend a bunch of money up front and get a quality tool that will last a long time. The other option is purchasing a cheap cordless tool that won’t last long, having to replace it later and thus spending more money. With cheap cordless tools it is common for the battery to fail before the physical tool making that tool completely unusable. Sure, another battery could be purchased but sometimes they cost just as much as the tool and battery combo originally did. So what’s a cordless tool user to do?

[EngergySaver] had a set of DeWalt cordless tools with a bunch of working batteries. He also had a cheap drill where the battery had died. His bundle of tools included two flashlights, one of which the case physically broke in half, probably from a clumsy drop. Instead of tossing the broken flashlight pieces in the garbage, [EngergySaver] kept them around for a while. Then one day he had the idea of combining the base of the broken DeWalt flashlight with the top of the old battery-less drill. He had the parts so why not?

The battery pack was 18 volt and the cheap drill expected 16.8 volts. [EngergySaver] figured the voltages were close enough and decided not to worry about the difference during his hack. He started by disassembling both the drill and flashlight down to the bare plastic housings. He marked an appropriate place to splice the handles and made some cuts. After the wiring was spliced together and the tool casings reassembled, a piece of sheet metal was cut and bent around the handle at the joint between flashlight and drill. Hose clamps hold the sheet metal tight around the handles, keeping the new hybrid tool together. And although we’re not crazy about the sheet metal and hose clamp method, it seems to be working just fine. With a little work and ingenuity [EngergySaver] resurrected an old tool for our favorite price; $0.

Human-Machine Interface Projects at TEI 2016

For many of us, interacting with computers may be as glorious as punching keys and smearing touch screens with sweaty fingers and really bad posture. While functional, it’s worth reimagining a world where our conversation with technology is far more intuitive, ergonomic, and engaging. Enter TEI, an annual conference devoted to human-computer interaction and a landmark for novel projects that reinvent the conventional ways we engage our computers. TEI isn’t just another sit-down conference to soak in a wealth of paper talks. It’s an interactive weekend that combines these talks with a host of workshops provided by the speakers themselves.

Last year’s TEI brought us projects like SPATA, digital calipers that sped up our CAD modeling by eliminating the need for a third hand, and TorqueScreen, a force-feedback mechanism for tablets and other handhelds.

Next February’s conference is no exception for new ways to interact with novel technology. To get a sense of what’s to come, here’s a quick peek into the past from last year’s projects:

Continue reading “Human-Machine Interface Projects at TEI 2016”

Caption CERN Contest – Dr. Frankenstein would be proud

Week 16 of the Caption CERN Contest just flew by, but not without sparking some cosmic comic genius in the minds of everyone who wrote a comment. Thanks to everyone who entered! If you followed last week’s blog post, you already know that this image isn’t an early POV display, or some sort of strange data display technique. It’s actually a spark chamber. Spark chambers use high voltage and noble gases to create a visible trail of cosmic rays. Since this image is dated 1979, well after spark chambers were used for hard science, we’re guessing it was part of a demonstration at CERN’s labs.

The Funnies:

  • “Here we see Doug playing a Massively multiplayer Pong game against his peers in the next building over.” – [John Kiniston]
  • “It said “Would you like to play a game?” and I said yes. Are those missile launch tracks?”- [jonsmirl]
  • “Before Arduino you needed a whole room full of equipment to blink LEDs!” – [mjrippe]

After two weeks as a runner-up, this week’s winner is The Green Gentleman with “‘Hang on, let me fix the vert-hold, and then get ready for a most RIGHTEOUS game of 3D PONG!’ Sadly, this CERN spinoff never made it to the market”

We’re sure [The Green Gentleman] will be very courteous to his fellow hackers in sharing his new Bus Pirate From The Hackaday Store! Congratulations [The Green Gentleman]!

Week 17

cern-17-smCoils, gleaming metal, giant domes, now this is a proper mad scientist image! The CERN scientists in this image seem to be working on a large metal device of some sort. It definitely looks like an electrode which would be at home either at CERN or the well equipped home lab of one Dr. Frankenstein’s. We don’t have a caption, but we do have a rough date of August, 1961. What is happening in this image? Are these scientists setting up an experiment, or plotting world domination?

You tell us!

This week we’re giving away a Logic Pirate from The Hackaday Store.

Add your humorous caption as a comment to the contest log. Make sure you’re commenting on the contest log, not on the contest itself.

As always, if you actually have information about the image or the people in it, let CERN know on the original image discussion page.

Good Luck!