[Robb] has had a little experience making lenses from scratch. His first attempt was for a DIY projector, and while the lens was a little blurry, it did work rather well for something carved out of a block of acrylic. Now he’s taking his experiments with lenses even further with DIY optics that turn everything into a funhouse mirror.
There were two techniques tested while making these lenses. The first was the old standby, CNC milling. A piece of acrylic was put in a CNC and carved with a 1/2″ ball mill. The second technique was 3D printing on a very fancy and very expensive Objet Connex 500. Neither of these methods produce a ready to use lens; to get a finished lens out of the machined or printed objects, [Robb] had to wet sand with 240, 320, 400, 600, 1000, 1500, and 2000 grit sandpaper. After a few hours worth of sanding, the parts were polished with a scratch remover.
Making a lens like this isn’t really that novel – it’s basically the same way lenses have been made for 500 years. The real trick here is making funhouse mirror style lenses. These lenses were created by raytracing in Rhino and Neon. It’s tricky; the index of refraction for acrylic is a little lower than glass, and the refraction for 3D photoresin is a bit higher than glass.
With those models in hand, it’s a relatively simple matter of making some very cool and very strange lenses.
Lumographic images are those patterns you see at the bottom of swimming pools. When water works as a lens, the light patterns of bright and dark are random and wandering based on the waves above. [Matthew] figured out a way to create fixed images from lens shape alone. The images only morph into view clearly when light shines at the proper angle. At near angles an eerie fun-house mirror effect appears, but too far off and it scatters unrecognisably.
The exact method for designing the optics is not explained, though we are sure someone in our readership could figure it out. The artist claims it to be a hundred year old million-variable math problem. The lenses are often quite thick and do not resemble much of anything. The effect however, is sharp, clear and detailed.
At first he suspected he needed astronomically-expensive military-grade 50 nanometer (0.000002″) precision machining for the lenses, but some friends in the autobody industry gave him a few tips to squeeze good enough accuracy from more affordable industrial machines. The technique also allows for images to appear from mirrors and internal reflections. It is probably not something you can 3D print or machine yourself, but it would be interesting to see someone try.
[Matthew]’s work is on display in the “Composite” gallery at the National Museum of Math in New York (MoMath). See the video after the break for a peak at the machinery he uses to manipulate the lenses to enhance the visuals in the exhibit.
Continue reading “Lumographic Images Created With Lens Only”
There are some types of projects that we see quite often here on Hackaday; 3D Printers, Development Boards and Video Game Hardware to name a few. Once in a while we see an optics-based project but those use pre-made lenses. [Peter] felt it was time to give home lens manufacturing a shot and sent in a tip about his experience.
The typical lens manufacturing process starts off by taking a piece of glass and manipulating it into a rough lens shape, either by removing material or heating the glass and forming it in a mold. These lens blanks are then lapped using progressively finer grits of abrasives until the final lens shape and surface finish are achieved. The tool used to lap the lens is very specialized and specific to one lens contour shape. This lapping process can be very time consuming (and therefore expensive) depending on the quality and size of the lens being made.
Continue reading “One Small Step For Magnification, One Giant Leap For Home Lens Manufacturing”
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.
[Chris Gammell] tipped us off that he’s building an online training program for learning electronics. The ten session course will cost money to take but you can get the goods for free if you’re one of the beta testers. We love to listen to The Amp Hour podcast which is just one of [Chris’] many endeavors.
Did you buy a Chromecast this week? We did, but we don’t have it in hand yet (ordered through Amazon). You can still get a look inside from the iFixit teardown.
Practice your Processing skills by using it to code a game of Pong.
A bit of lighter fluid and a hacked insert will get you a flaming wallet. We guess this is a different type of an anti-pickpocket device. [Thanks Stephen]
[Brain] used a $1.50 magnifying lens to help his Raspberry Pi camera module read QR codes better.
We really like [Aaron Christophel’s] LED matrix clock (translated). He started from a marquee that must be at least a decade old. He stripped it down and figured out how to drive it using a Sanguino as a controller.
Glass work is always a feast for the eyes, especially when it is hot glass. Watch as a Nikkor lens is made from beginning to end. It is wonderful to see the care taken to search by eye for defects, refraction issues, clarity etc. It may just be for the video, but it seems that the workers truly do take pride in their product.
What I found somewhat surprising was the amount of work that went into refining the glass BEFORE it was even put into a lens mold. I would have assumed that much of the work would have come after.
[Martin Melchior] wanted to use an older Sigma lens with his Canon camera. The problem in trying to do so is that the camera uses a different communications protocol than the lens is expecting. But if you don’t mind cracking it open and doing a little microcontroller work you’ll be using the lens in no time.
The hack uses an ATtiny24 chip, two resistors, and a capacitor. You won’t need to do any coding, but you do need to burn the firmware to the chip (you can use an Arduino if you don’t have a proper AVR programmer). There’s plenty of room for the add-on hardware inside the lens so after reassembling the enclosure you won’t even be able to tell that the unit was altered. Unfortunately it doesn’t look like [Martin] took any pictures of the lens with his added electronics, but the schematic he posted should be enough for you to get the job done yourself.
If you’re into these types of DSLR hacks you should try something extreme, like using view camera parts with your modern camera.