You may remember that earlier this year Leap Motion revealed Project North Star, a kind of open-source reference design for an Augmented Reality (AR) headset. While it’s not destined to make high scores in the fashion department, it aims to be hacker-friendly and boasts a large field of view. There’s also an attractive element of “what you see is what you get” when it comes to the displays and optical design, which is a good thing for hackability. Instead of everything residing in a black box, the system uses two forward-facing displays (one for each eye) whose images are bounced off curved reflective lenses. These are essentially semitransparent mirrors which focus the images properly while also allowing the wearer to see both the displays and the outside world at the same time. This co-existence of both virtual and real-world visuals are a hallmark of Augmented Reality.
A serious setback to the aspiring AR hacker has been the fact that while the design is open, the lenses absolutely are not off the shelf components. [Smart Prototyping] aims to change that, and recently announced in a blog post that they will be offering Project North Star-compatible reflective lenses. They’re in the final stages of approving manufacture, and listed pre-orders for the lenses in their store along with downloadable 3D models for frames.
When Leap Motion first announced their open-source AR headset, we examined the intruiguing specifications and the design has since been published to GitHub. At the time, we did note that the only option for the special lenses seemed to be to CNC them and then spring for a custom reflective coating.
If the lenses become affordable and mass-produced, that would make the design much more accessible. In addition, anyone wanting to do their own experiments with near-eye displays or HUDs would be able to use the frame and lenses as a basis for their own work, and that’s wonderful.
[PWalsh] has a clever idea for learning and experimenting with basic optics: instead of using actual lenses, he’s using clear pieces of laser-cut acrylic cut into lens profiles instead. They are much easier to make, mount, adjust, and handle while still bending light in the same basic ways. It allows for simple hands-on experimentation with plenty of visual feedback – perfect for beginners.
This idea is part of [PWalsh]’s low-cost optics bench project, which uses laser-cut plastic to create adjustable optics bench components. We’ve covered this project before, but [PWalsh] expanded the idea with the concept of these simple laser-cut optics for basic experimentation; an addition that requires no additional tools and only a small amount of material. Features and value added for nearly zero cost is something we always love to see!
Continue reading “Low Cost Optics Bench Project – Now with Lasercut Optics”
Experimenting with optics can be great fun and educational. Trouble is, a lot of optical components are expensive. And other support paraphernalia such as optical benches, breadboards, and rails add to the cost. [Peter Walsh] and his team are working on designing a range of low-cost, easy to build, laser cut optics bench components. These are designed to be built using commonly available materials and tools and can be used as low-cost teaching tools for high-schools, home experimenters and hacker spaces.
They have designed several types of holders for mounting parts such as lasers, lenses, slits, glass slides, cuvettes and mirrors. The holder parts are cut from ¼ inch acrylic and designed to snap fit together, making assembly easy. The holders consist of two parts. One is a circular disk with three embedded neodymium magnets, which holds the optical part. The other is the base which has three adjustment screws which let you align the optical part. The magnets allow the circular disk to snap on to the screws on the base.
A scope for improvement here would be to use ball plunger screws instead of the regular ones. The point contact between the spherical ball at the end of the screw and the magnet can offer improved alignment. A heavy, solid table with a ferrous surface such as a thick sheet of steel can be used as a bench / breadboard. Laser cut alignment rods, with embedded magnets let you set up the various parts for your experiment. There’s a Wiki where they will be documenting the various experiments that can be performed with this set. And the source files for building the parts are available from the GitHub repository.
Check out the two videos below to see how the system works.
Continue reading “Hackaday Prize Entry: Optical Experiments Using Low Cost Lasercut Parts”
[Florian] is hyped for Google Cardboard, Oculus Rifts, and other head mounted displays, and with that comes an interest in lenses. [Floian] wanted to know if it was possible to create these lenses with a 3D printer. Why would anyone want to do this when these lenses can be had from dozens of online retailers for a few dollars? The phrase, ‘because I can’ comes to mind.
The starting point for the lens was a CAD model, a 3D printer, and silicone mold material. Clear casting resin fills the mold, cures, and turns into a translucent lens-shaped blob. This is the process of creating all lenses, and by finely sanding, polishing, and buffing this lens with grits ranging from 200 to 7000, this bit of resin slowly takes on an optically clear shine.
Do these lenses work? Yes, and [Florian] managed to build a head mounted display that can hold an iPhone up to his face for viewing 3D images and movies. The next goal is printing prescription glasses, and [Florian] seems very close to achieving that dream.
The last time we saw home lens making was more than a year ago. Is anyone else dabbling in this dark art? Let us know in the comments below and send in a tip if you have a favorite lens hack in mind.
We can’t see much without our glasses (which is why our habit of shaving in the shower often ends badly). Our glasses cost a bundle, but we wear them every waking moment so it’s worth it. But only recently did we break down and spring for prescription sunglasses. However, when it comes to sports we don’t pony up the dough for dedicated specs. Here’s a hack that will change that. If you’ve still got your last set of glasses on hand hack up the lenses for swimming goggles or other applications.
In this case [Dashlb’s] lenses were already small enough to fit in the goggles. He simply added a bead of Sugru around the edges to hold the lenses in place. But if you do need to cut them to size aligning the lenses with your eyes is important, so we suggest the following: have a buddy stand in front of you and mark the center of your pupil on the glasses, as well as the goggles. If you need to cut down the lenses (which are probably a type of polycarbonate) just make sure the marks match up before doing any cutting.
We might give this a try with some wrap-around sunglasses to make an inexpensive pair of prescription cycling shades.
Camera lenses are expensive and if you’re like us, you can easily find really cheap lenses that your camera can’t use. [Sam] has a Canon EOS and a bunch of old-school FD lenses at his disposal. There’s one problem though: using these old lenses with an adapter means focusing at infinity is out of the question. Thankfully, he put up a few videos (part 1, part 2, and part 3) walking through the process of modifying an FD lens for his new camera.
To do the modification for the FD lens, all that’s needed is some epoxy, a screw driver, and an M42 to EF adapter. After disassembling the back of the FD lens, [Sam] mounted the M42 adapter on his camera and held the lens up to check the minimum focusing distance. A bit of grinding or a few metal shims ensure that the lens is in the right position.
The next step is making sure the aperture can still be controlled. [Sam] goes through this in part two of his video. A little bit of dremeling takes care of all the hard work. The lens is finally attached to the M42 adapter with a tiny bit of epoxy, and the conversion is complete.
While [Sam] could have put up a few close up pics of his build, he goes through every step of the process very well. Check out the embedded videos after the break.
Continue reading “Canon FD lenses on an EOS mount”
Reader [Harald] sent us this sweet Pringles can macro photography hack from way back in 2005. Using a Pringles can and a standard Cannon 50mm MKII lens, they have produced some amazing results. The image above is the tip of a ballpoint pen. Not only does he go through the steps to make it, but then goes in depth on how to best set your camera and other good practices for macro photography. Pringles cans aren’t just for holding chips and making wireless antenna.
We’ve covered several macro photography rigs before, like how to do macro photography with your iPhone, or with a flip camera, and even how to build a massive laser controlled macro photography setup.