Mastering Stop Motion Through Machine Learning

September 20, 2021 by Tom Nardi 13 Comments

Stop motion animation is notoriously difficult to pull off well, in large part because it’s a mind-numbingly slow process. Each frame in the final video is a separate photograph, and for each one of those, the characters and props need to be moved the appropriate amount so that the final result looks smooth. You don’t even want to know how long Ben Wyatt spent working on Requiem for a Tuesday, though to be fair, it might still get done before the next Avatar.

But [Nick Bild] thinks his latest project might be able to improve on the classic technique with a dash of artificial intelligence provided by a Jetson Xavier NX. Basically, the Jetson watches the live feed from the camera, and using a hand pose detection model, waits until there’s no human hand in the frame. Once the coast is clear, it takes a shot and then goes back to waiting for the next hands-free opportunity. With the photographs being taken automatically, you’re free to focus on getting your characters moving around in a convincing way.

If it’s still not clicking for you, check out the video below. [Nick] first shows the raw unedited video, which primarily consists of him moving three LEGO figures around, and then the final product produced by his system. All the images of him fiddling with the scene have been automatically trimmed, leaving behind a short animated clip of the characters moving on their own.

Now don’t be fooled, it’s still going to take awhile. By our count, it took two solid minutes of moving around Minifigs to produce just a few seconds of animation. So while we can say its a quicker pace than with traditional stop motion production, it certainly isn’t fast.

Machine learning isn’t the only modern technology that can simplify stop motion production. We’ve seen a few examples of using 3D printed objects instead of manually-adjusted figures. It still takes a long time to print, and of course it eats up a ton of filament, but the mechanical precision of the printed scenes makes for a very clean final result.

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Automatic Microfiche Scanner Digitizes Docs

September 17, 2021 by Tom Nardi 18 Comments

While the concept might seem quaint to us today, microfiche was once a very compelling way to store and distribute documents. By optically shrinking them down to just a few percent of their original size, hundreds of pages could be stored on a piece of high-resolution film. A box of said films could store the equivalent of several gigabytes of text and images, and reading them back only required a relatively simple projection machine.

As [Joerg Hoppe] explains in the write-up for his automatic microfiche scanner, companies such as Digital Equipment Corporation (DEC) made extensive use of this technology to distribute manuals, schematics, and even source code to their service departments in the 70s and 80s. Luckily, that means hard copies of all this valuable information still exist in excellent condition decades after DEC published it. The downside, of course, is that microfiche viewers aren’t exactly something you can pick up at the local Big Box electronics store these days. To make this information accessible to current and future generations, it needs to be digitized.

The camera panning over a full DEC microfiche sheet.

[Joerg] notes there are commercial services that would do this for you, but the prices are just too high to be practical for the hobbyist. The same for turn-key microfiche scanners. Which is why he’s developed this hardware and software system specifically to digitize DEC documents. The user enters in the information written on the top of the microfiche into the software, and then places it onto the machine itself which is based on a cheap 3D printer.

The device moves a Canon DSLR camera and appropriate magnifying optics in two dimensions over the film, using the Z axis to fine-tune the focus, and then commands the camera to take an image of each page. These are then passed through various filters to clean up the image, and compiled into PDFs that can be easily viewed on modern hardware. The digital documents can be further run though optical character recognition (OCR) so the text can be easily searched and manipulated. In the video after the break you can see that the whole process is rather involved, but once the settled into the workflow, [Joerg] says his scanner can digitize 100 pages in around 10 minutes.

A machine like this is invaluable if you’ve got a trove of microfiche documents to get through, but if you’ve just got a sheet or two you’d like to take a peek at, [CuriousMarc] put together a simple rig using a digital microscope and a salvaged light box that should work in a pinch.

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DIY Laser Speckle Imaging Uncovers Hidden Details

September 17, 2021 by Tom Nardi 31 Comments

It sure sounds like “laser speckle imaging” is the sort of thing you’d need grant money to experiment with, but as [anfractuosity] recently demonstrated, you can get some very impressive results with a relatively simple hardware setup and some common open source software packages. In fact, you might already have all the components required to pull this off in your own workshop right now and just not know it.

Anyone who’s ever played with a laser pointer is familiar with the sparkle effect observed when the beam shines on certain objects. That’s laser speckle, and it’s created by the beam reflecting off of microscopic variations in the surface texture and producing optical interference. While this phenomenon largely prevents laser beams from being effective direct lighting sources, it can be used as a way to measure extremely minute perturbations in what would appear to be an otherwise flat surface.

In this demonstration, [anfractuosity] has combined a simple red laser pointer with a microscope’s 25X objective lens to produce a wider and less intense beam. When this diffused beam is cast onto a wall, the speckle pattern generated by the surface texture can plainly be seen. What’s not obvious to the naked eye is that touching the wall with your hand actually produces a change in the speckle pattern. But if you take high-resolution before and after shots, the images can be run through OpenCV to highlight the differences and reveal a ghostly hand-print.

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3D Printing Your Own Sturdy Lens Caps

August 31, 2021 by Lewin Day 13 Comments

Lens caps are important for protecting expensive camera lenses from damage. Dust, grit, and other nasty things will all quickly spoil the quality of a shot, and can even permanently damage a lens if you’re unlucky. However, lens caps are also lost quite easily. Thus, it’s useful to be able to make your own, and [DSLR CNC DIY] has the low down on how to do it.

The benefit of printing your own lens caps is customization. No matter the oddball size and shape of your lens, when you’re 3D printing your own cap, you can design it to fit. The video also shows off the benefits of being able to embed text right into the body of the cap, so you’re never confused as to which cap goes with which lens. The caps use the metal lever from a binder clip in order to provide the clamping force necessary to hang on to the lens. It’s an improvement over some living-hinge designs that grow weaker over time.

Overall, if you’ve got a bunch of lenses that need a new cap, this could be the project for you. It’s also likely much cheaper and easier than hunting down replacement caps for obscure lenses online. Alternatively, contemplate what you could do with fancy lens adapters. Video after the break. Continue reading “3D Printing Your Own Sturdy Lens Caps” →

Better 3D Scans Through A Slowed Down Turntable

August 31, 2021 by Tom Nardi 6 Comments

3D scanners aren’t cheap, and the last thing you want to see after purchasing one is bad data. But that’s what [Dave Does] and others were getting from their Revopoint POP scanners until some communal brainstorming uncovered the reason: the motorized turntable that came with the Kickstarter edition of the product was spinning too fast for the software to accurately keep track of the object. So he decided to replace the stepper motor controller in his turntable and document the process for anyone else who’s scanner might be struggling.

In the video below, [Dave] pops open the plastic case of the turntable and reveals a pretty sparse interior. There’s an incredible amount of empty space inside, and even some mounting studs to screw down new components, should you want to get into some hardcore upgrades. But for his purposes, a generic stepper motor controller that featured a potentiometer to adjust the speed was enough. He found a suitable board online for around $5 USD, and got to designing a 3D printed bracket that mates up to the existing screw holes on the turntable.

But it’s not exactly a drop-in replacement. For one thing, you’ve got to pop a hole in the side of the enclosure for the potentiometer knob to stick out of. You’ve also got to solder wires coming from the original DC jack and power switch to the new board to get it hooked up, but at least the motor plugs right in. In the video below, you can see [Dave] demonstrate the impressively deep throttle capability of the new driver.

If you’d rather build than buy, we’ve covered some impressive DIY turntables in the past that could fit the bill nicely, from automatic models that handle camera control to fully 3D printed versions that you’ve got to crank yourself.

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Pedal Operated Cable Cam For Hands Free Video

August 25, 2021 by Danie Conradie 3 Comments

[Vintage Backyard RC] has built a nice little RC track in his backyard, and wanted a motorized dolly system to capture footage along the main straight with his GoPro. Using only junk box parts, he created a simple pedal operated RC cable dolly. (Video, embedded below.)

[Vintage Backyard RC] first experimented with a high speed car running on a length of model train track. However, it was bumpy at high speed, the track is expensive, and it needs 50 V running through the open tracks. The new cable cam gives a much smoother ride, and cost almost nothing with his supply of old RC gear. The cable cam is powered by a brushed motor from an RC airplane, running with plastic wheels on some weed trimmer line. Control is provided by an old 27 MHz RC system, with the controller’s internals transplanted into an old wah-wah guitar pedal.

The non-geared motor can drive the cable much faster than required, so [Vintage Backyard RC] needs to exercise some careful foot control to run it at a reasonable speed. This is easier said than done while also controlling an RC car with his hands, so he plans to replace the RC system with a newer 2.4 GHz system software end-point limits. We would be reaching for the ESP32 or any other microcontroller with wireless that we’ve come to know, but it’s worth remembering that most people are not familiar with these tools.

This is definitely the most minimalist cable cam we’ve covered this year, but just demonstrates how simple they can be to build. You can always upgrade to a sleek folding frame from 3D printed parts, and add machine vision and long range video streaming.

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Everything You Always Wanted To Know About Radioactive Lenses

August 7, 2021 by Al Williams 45 Comments

We think of radioactive material as something buried away in bunkers with bombs, power plants, and maybe some exotic medical equipment. But turns out, there are little bits of radiation in the water, our soil, bananas, granite countertops, smoke detectors, and even some camera lenses. Camera lenses? A few decades ago, camera companies added rare elements like thorium to their glass to change the optical properties in desirable ways. The downside? Well, it made the lenses somewhat radioactive. A post by [lenslegend] explains it all.

Exotic elements such as Thorium, Lanthanum and Zirconium are added to glass mixtures to create the high refractive indexes necessary in sophisticated lens designs. Selection of premium quantities of glass from the large glass pots, stringent spectrophotometric tests after stress and strain checks provide the valuable raw glass for ultimate use in lens elements.
—Konica Hexanon Lens Guide, Konica Camera Company, 1972

According to [lenslegend] the practice started in 1945 with Kodak. However, by the 1980s, consumer distaste for radioactive things and concern for factory workers ended the production of hot camera lenses.

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