Recreating A Camera Shot

June 14, 2022 by Matthew Carlson 14 Comments

People rolling off shields and spears clashing against swords as the camera zooms in and out wildly makes the hallmark action sequences in the movie 300 so iconic. Unfortunately, achieving this effect wasn’t particularly easy. Three cameras were rolling, each with a different lens (100mm, 50mm, and 21mm) to capture a different view of the same scene. In post-production, you can dramatically switch between the three cameras since the shot is synchronized. The folks over at [Corridor Crew] wanted to recreate the effect, but rather than create a custom mount to hold three expensive cameras, they 3d printed a custom mount to hold three costly smartphones.

While there are three cameras on the back of most phones, most phones can’t shoot in slo-mo from all cameras simultaneously. So they would need a rig to hold three phones. The first design was simple and just brackets to hold phones. While nice and sturdy, getting the phones in or out wasn’t easy, and getting to the record button was tricky. iPhones have this handy little magnetic ring on the back. They had a bracket that worked pretty well after a few iterations on the design and some printer issues. Since each camera has optical image stabilization, it is easy for the lenses to get out of alignment, which can mar the shot. However, they somewhat covered up the effect in post. With a working prototype, the only thing left to do was to slice a bunch of piñatas in slow motion with a thrumming soundtrack.

We love seeing exciting camera setups and iterating to find something that works. This dual-camera setup has a very different goal and tries to lean into the parallax effect rather than hide it. Video after the break.
Continue reading “Recreating A Camera Shot” →

Stop-Motion Angels In The Light Field

May 3, 2022 by Matthew Carlson No comments

Baseball jokes aside, holograms have been a dream for decades, and with devices finally around that support something like them, we have finally started to wonder how to make content for them. [Mike Rigsby] recently entered his stop-motion holographic setup into our sci-fi contest, and we love the idea.

Rather than a three-dimensional model or a 2d picture with pixels, the Looking Glass light field display supports a series of images as quantized points (hence light field). As you move around an object, images are interpolated between the frames you do know, giving a pretty convincing effect. In a traditional stop motion animation, you need to take anywhere between 12-24 frames to equal about one second of animation. Now that you need to take 48 pictures for one frame, over 1152 pictures for just one second of animation. Two problems quickly appear, how to take photographs accurately from the same position every time and how do you manage the deluge of photos sensibly. [Mike] started with a wooden stage for his actors. A magnet was mounted to the photo rail carriage, and a sensor allowed it to detect that it was in the same spot. An Arduino controls the rail, reads the magnet via a sensor, and controls the camera shutter. The DSLR he’s using can’t do that many frames per second, but that’s a problem for another sci-fi contest.

Holographic-ish displays are finally here, and they’re getting better. But if a display isn’t your speed, perhaps some laser-powered glasses can be the holographic experience you’re looking for?

This project was an entry into the 2022 Sci-Fi Contest. Check out all of the winning entries here.

Clever Stereo Camera Uses Sony Wireless Camera Modules

April 30, 2022 by Jenny List 13 Comments

Stereophotography cameras are difficult to find, so we’re indebted to [DragonSkyRunner] for sharing their build of an exceptionally high-quality example. A stereo camera has two separate lenses and sensors a fixed distance apart, such that when the two resulting images are viewed individually with each eye there is a 3D effect. This camera takes two individual Sony cameras and mounts them on a well-designed wooden chassis, but that simple description hides a much more interesting and complex reality.

Sony once tested photography waters with the QX series — pair of unusual mirrorless camera models which took the form of just the sensor and lens. A wireless connection to a smartphone allows for display and data transfer. This build uses two of these, with a pair of Android-running Odroid C2s standing in for the smartphones. Their HDMI video outputs are captured by a pair of HDMI capture devices hooked up to a Raspberry Pi 4, and there are a couple of Arduinos that simulate mouse inputs to the Odroids. It’s a bit of a Rube Goldberg device, but it allows the system to use Sony’s original camera software. An especially neat feature is that the camera unit and display unit can be parted for remote photography, making it an extremely versatile camera.

It’s good to see a stereo photography camera designed specifically for high-quality photography, previous ones we’ve seen have been closer to machine vision systems.

Digital To Analog In The Darkroom

April 27, 2022 by Bryan Cockfield 7 Comments

As the world becomes more and more digital, there are still a few holdouts from the analog world we’ve left behind. Vinyl records are making quite the comeback, and film photography is still hanging on as well. While records and a turntable have a low barrier for entry, photography is a little more involved, especially when developing the film. But with the right kind of equipment you can bridge the gap from digital to analog with a darkroom setup that takes digital photographs and converts them to analog prints.

The project’s creator, [Muth], has been working on this project since he found a 4K monochrome display. These displays are often used in resin 3D printers, but he thought he could put them to use developing photographs. This is much different from traditional darkroom methods, though. The monochrome display is put into contact with photo-sensitive paper, and then exposed to light. Black pixels will block the light while white pixels allow it through, creating a digital-to-analog negative of sorts. With some calibration done to know exactly how long to expose each “pixel” of the paper, the device can create black-and-white analog images from a digital photograph.

[Muth] notes that this method isn’t quite as good as professional print, but we wouldn’t expect it to be. It creates excellent black-and-white prints with a unique method that we think generates striking results. The 4K displays needed to reproduce this method aren’t too hard to find, either, so it’s fairly accessible to those willing to build a small darkroom to experiment. For those willing to go further, take a look at some other darkroom builds we’ve seen in the past.

Continue reading “Digital To Analog In The Darkroom” →

Scanning Receipts Proves Trickier Than Anticipated

April 21, 2022 by Tom Nardi 25 Comments

It’s one of those things that certainly sounds simple enough: take a picture of a receipt, run it through optical character recognition (OCR), and send the resulting information to whatever expense-tracking website or software you wish. There are companies that offer such a service, so it can’t be too difficult to replicate on your own…right?

That’s what [Marcel Robitaille] thought when he set out to create his homebrew “Receipt Ingestion” system, anyway. But in reality it took so much time to troubleshoot and implement that he says it would have been faster to just enter in all his receipts by hand. We’re happy he stuck with it though, otherwise you wouldn’t be reading about it on Hackaday, and we wouldn’t be able to learn anything from the detailed account he’s provided.

It only took an evening to hack together a rough demo, and the initial results were very promising. The code could detect the edges of the receipt, rotate the captured image appropriately, and then pull out the critical information such as date, total amount, business name, etc. He was then able to decipher the API for Splitwise, an online service for splitting bills, by capturing the data sent by his browser while adding a new bill. With this information, writing up some Python code to push his captured data into the service was trivial. So far, so good.

But like so many horror films that begin with a happy family starting a new life in a beautiful home, there was a monster lurking in the shadows. It’s one thing to capture data from perfectly clean and flat receipts, but quite another to get any useful info out of one that spent half the day crumpled up in your back pocket. The promising proof of concept that worked a treat under controlled conditions failed completely in the real-world, with [Marcel] reporting that only 1 in 5 receipts he tried to scan actually went through.

In the end, [Marcel] realized that the best way to handle the unreliable condition of the receipts was to focus on a different object in the image. He came up with a QR code marker that he could put on the table with the receipt to be scanned, which his software can use as a known point of reference. This greatly improves the reliability of the image rotation and transformation, which in turn makes the OCR more reliable. It also makes it much easier to tell which images need to be scanned — if there’s no QR code found, the software just skips that shot and keeps looking.

The unique challenges of digitizing large amounts of printed content using OCR makes for some fascinating problem solving, and we’re glad [Marcel] shared this particular story with us. While there’s still some edge cases that need chasing down, he’s using the software on a nearly daily basis, and has posted it up on GitHub for anyone who might wish to build on his efforts.

Developing Your Own Digital Film

April 20, 2022 by Matthew Carlson 5 Comments

In the olden days, you would have a roll of film that you could take to your local drug store and have them develop it. But a serious photographer would likely develop their own photos to maintain complete creative control. While photo editing software has largely replaced the darkroom of old, the images are still held on physical media, and that means there’s room for improvement and customization. In an article for photofocus, [Joseph Nuzzo] shows how you can make your own CFexpress card — the latest and greatest in the world of digital camera storage tech — for less than $100 USD.

The idea here is pretty simple, as CFexpress uses PCIe with a different connector. Essentially all you have to do is get a M.2 2230 NVMe drive and put it into an adapter. In this case [Joseph] is using a turn-key model from Sintech, but we’ve shown in the past how you can roll your own.

Now you might not give it much thought normally, but NVMe devices get pretty hot. This usually isn’t problem inside a large computer case, where they often have large amounts of air blowing over them. But inside a camera you need to dissipate that heat, so thermal compound is a must. With everything screwed together, you have your own card that’s faster and cheaper than commercial offerings.

It’s no secret that there’s a lot of love for NVMe. It’s easy, fast, and adaptable. Since the M.2 slot format includes SATA and PCIe, there’s a likely chance there is a PCIe bus in many cameras. The PCIe bus on the Pi has been convenient for hacking, and we wonder what sort of hacks are out there for cameras.

Review: Vizy Linux-Powered AI Camera

April 11, 2022 by Donald Papp 14 Comments

Vizy is a Linux-based “AI camera” based on the Raspberry Pi 4 that uses machine learning and machine vision to pull off some neat tricks, and has a design centered around hackability. I found it ridiculously simple to get up and running, and it was just as easy to make changes of my own, and start getting ideas.

Person and cat with machine-generated tags identifying them — Out of the box, Vizy is only a couple lines of Python away from being a functional Cat Detector project.

I was running pre-installed examples written in Python within minutes, and editing that very same code in about 30 seconds more. Even better, I did it all without installing a development environment, or even leaving my web browser, for that matter. I have to say, it made for a very hacker-friendly experience.

Vizy comes from the folks at Charmed Labs; this isn’t their first stab at smart cameras, and it shows. They also created the Pixy and Pixy 2 cameras, of which I happen to own several. I have always devoured anything that makes machine vision more accessible and easier to integrate into projects, so when Charmed Labs kindly offered to send me one of their newest devices, I was eager to see what was new.

I found Vizy to be a highly-polished platform with a number of truly useful hardware and software features, and a focus on accessibility and ease of use that I really hope to see more of in future embedded products. Let’s take a closer look.

Continue reading “Review: Vizy Linux-Powered AI Camera” →