A Bullet Time Video Booth You Can Build

May 27, 2023 by Dave Rowntree 8 Comments

[Sebastian Staacks] built a video booth for his wedding, and the setup was so popular with family, that it was only fitting to do one better and make some improvements to the setup, Matrix-style. The “bullet time” video effect was introduced by the classic movie franchise and makes for a splendid video transition effect for video montages.

Hardware-wise, the effect is pretty expensive, requiring many cameras at various angles to be simultaneously triggered, in order to capture the subject in a fixed pose with a rotating camera. Essentially you need as many cameras as frames in the sequence, so even at 24 frames per second (FPS), that’s a lot of hardware. [Sebastian] cheated a bit, and used a single front-facing camera for the bulk of the video recording, and twelve individual DSLRs covering approximately 90 degrees of rotation for the transition. More than that is likely impractical (not to mention rather expensive) for an automated setup used in as chaotic an environment as a wedding reception! So, the video effect is quite the same as in the movies, as this is a fixed pose, but it still looks pretty good.

A Pico-W hidden in there providing a BT connected interface button

[Sebastian] did consider going down the Raspberry Pi plus Pi-cam route, but once you add in a lens and the hassle of the casing and mounting hardware, not to mention availability and cost, snagging a pile of old DLSRs looks quite attractive. Connectivity to the camera is a simple 3.5 mm jack for the focus and trigger inputs, with frames read out via a USB connection.

For practical deployment, the camera batteries were replaced with battery eliminator adapters which step-up the 5 V from the USB connection to the 7.4 V the cameras need, but the current spike produced by the coordinated trigger of all twelve cameras overwhelmed any power supply available. The solution, to be practical, and not at all elegant, is to just have lots of power supplies hidden in a box. Sometimes you’ve just got a job to do.

Reproducing this at home might be a bit awkward unless you have exactly the same hardware to hand, but the principles are sound, and there are a few interesting details to dig into, if you were so inclined.

We’ve seen a few takes on the bullet-time effect over the years. We featured a Raspberry Pi-based hack, a couple of years back, and earlier still, someone even built a rig to take bullet-time videos of Tesla coil discharges, because why not?

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A Vintage Polaroid Camera Goes Manual

May 18, 2023 by Jenny List 5 Comments

There once was a time when all but the most basic of fixed focus and aperture cameras gave the photographer full control over both shutter speed and f-stop. This allowed plenty of opportunity to tinker but was confusing and fiddly for non-experts, so by the 1960s and ’70s many cameras gained automatic control of those functions using the then quite newly-developed solid state electronics. Here in 2023 though, the experts are back and want control. [Jim Skelton] has a vintage Polaroid pack film camera he’s using with photographic paper as the film, and wanted a manual exposure control.

Where a modern camera would have a sensor in the main lens light path and a microcontroller to optimize the shot, back then they had to make do with a CdS cell sensing ambient light, and a simple analog circuit. He considered adding a microcontroller to do the job, but realized that it would be much simpler to replace the CdS cell with a potentiometer or a resistor array. A 12-position switch with some carefully chosen resistor values was added, and placed in the camera’s original battery compartment. The final mod brought out the resistors and switch to a plug-in dongle allowing easy switching between auto and switched modes. Result – a variable shutter speed Polaroid pack camera!

Sadly the film for the older Polaroid cameras remains out of production, though the Impossible Project in the Netherlands — now the heirs to the Polaroid name — brought back some later versions and have been manufacturing them since 2010. Hackers haven’t been deterred though and have produced conversions using Fuji Instax film and camera components, as with this Polaroid portrait camera, and [Jim]’s own two-camera-hybrid conversion.

A Non-Destructive Digital Back For A Classic Leica

May 12, 2023 by Jenny List 16 Comments

As digital photography has become so good, perhaps just too good, at capturing near-perfect pictures, some photographers have ventured back into the world of film. There they have found the imperfections requiring technical skill to cope with that they desire, but they’ve also come face-to-face with the very high cost and sometimes sketchy availability of film stocks. From this has come the so-called post-digital movement which marries analog cameras and lenses with digital sensors, and of this a particularly nice example comes from [Michael Suguitan]. He’s taken a classic Leica M2 rangefinder camera, and built a new back for it containing a Raspberry Pi Zero and sensor.

Perhaps the best thing about this conversion, and something which should propagate forward into other builds, is the way it does not hack or modify the original camera beyond the replacement of the already-removable back. A vintage Leica is a pricey item, so it would be a foolhardy hacker who would proceed to gut it for a digital conversion. Instead he’s mounted everything that makes a digital camera, the sensor, Pi Zero, and screen board, behind the camera body. The Pi shutter trigger comes from the Leica’s flash terminal, meaning that there’s plenty of time for it to take a photo while the shutter is open.

He’s admirably preserved the usage and properties of the Leica, and his photographs as can be seen in the video below the break bear testament to what is possible with the camera. He still has to work with the tiny sensor size though, meaning that all photographs are at a much higher zoom level than on the original. We would love to see a camera conversion like this one that incorporates appropriate lenses to bring the picture to focus on this small sensor.

We won’t own a Leica any time soon, but we like this conversion. It’s by far the most sympathetic, but it’s not the first rangefinder conversion we’ve seen.

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Machine Vision Automates Trainspotting With Unique Full-Length Portraits

May 2, 2023 by Dan Maloney 11 Comments

As hobbies go, trainspotting is just as valid a choice as any — we don’t judge. But it does present certain logistical challenges, such as having to be in visual range of a train to be able to spot it. There’s also the fact that trains are very large objects, and they tend to move very fast. What’s a railfan to do?

If you’re also technically minded, you might try building an automatic trainspotting bot like [jo-m] has. It looks like the hardware end of “Trainbot” is pretty simple since it has been tested on both x86 and Raspberry Pi, and supports both video4linux and Pi cam. The magic is in the software, which is able to detect a train entering the frame, record images, and then stitch them together into one long image. The whole thing is coded in Go and has some interesting bits, like a custom image patch mapping package.

Trainbot gives an unusual view of a train, one that most of us accustomed to watching a train pass at a crossing have never seen. By stitching small chunks of the train as it passes, Trainbot is able to show the entire train in a single image, which would be impossible to do except for being very, very far away from the track. [jo-m] also built a web interface for Trainbot where you can check out the comings and goings yourself. Each passing train’s image is accompanied by data like its velocity and acceleration, length of the train, and time of passage. There’s also a GIF of the original source video, which is pretty cool.

Here in the States, we don’t have a lot of passenger trains to spot, but we do have some really long freight trains. It’d be interesting to see how this works with a train that’s over a mile long; that would be quite an image. Looks like someone at least has the hardware in place to give it a try.

Building A Motorized Pan Tilt Rig For Filming

April 21, 2023 by Lewin Day 3 Comments

Today, anyone can shoot video because cameras are cheap and readily available. But if you want to do fancy Hollywood-style moving shots, you’ll need somebody to point the thing — or a machine to do it for you. [Giovanni Aggiustatutto] went the latter route with this mechanized pan-tilt build.

The build relies on stepper motors for clean and accurate movement on both axes. Belt drives are used to step down the output of the motors for greater torque. The pan-tilt mechanism itself is built from a combination of 3D printed parts paired with wooden components and a pair of aluminium tubes for rigidity. The whole assembly comes with a standard mount for use with a regular tripod. An Arduino Uno runs the show, using TMC2208 stepper drivers to command the motors. A control pad featuring a joystick and buttons is used for control, with an LCD to provide useful feedback to the user.

Pan-tilt systems are more typically used for security purposes, but we like the application to creative work here.

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Raspberry Pi Camera Conversion Leads To Philosophical Question

April 18, 2023 by Jenny List 31 Comments

The Raspberry Pi HQ camera module may not quite reach the giddy heights of a DSLR, but it has given experimenters access to a camera system which can equal the output of some surprisingly high-quality manufactured cameras. As an example we have a video from [Malcolm-Jay] showing his Raspberry Pi conversion of a Yashica film camera.

Coming from the viewpoint of a photographer rather than a hardware person, the video is particularly valuable for his discussion of the many lens options beyond a Chinese CCTV lens which can be used with the platform. It uses only the body from the Yashica, but makes a really cool camera that we’d love to own ourselves. If you’re interested in the Pi HQ camera give it a watch below the break, and try to follow some of his lens suggestions.

The broken camera he converted is slightly interesting, and raises an important philosophical question for retro technology geeks. It’s a Yashica Electro 35, a mid-1960s rangefinder camera for 35 mm film whose claim to fame at the time was its electronically controlled shutter timing depending on its built-in light meter. The philosophical question is this: desecration of a characterful classic camera which might have been repaired, or awesome resto-mod? In that sense it’s not just about this project, but a question with application across many other retro tech fields.

A working Electro 35 is a fun toy for an enthusiast wanting to dabble in rangefinder photography, but it’s hardly a valuable artifact and when broken is little more than scrap. One day we’d love to see a Pi conversion with a built-in focal length converter allowing the use of the original rangefinder mechanism, but we’ll take this one any day!

How about you? Would you have converted this Yashica, repaired it somehow, or just hung onto it because you might get round to fixing it one day? Tell us in the comments!

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Your Fuji Digital Camera Is Hackable

April 8, 2023 by Jenny List 9 Comments

There was a time when a digital camera was a surprisingly simple affair whose on-board processor didn’t have much in the way of smarts beyond what was needed to grab an image from the sensor and compress it onto some storage. But as they gained more features, over time cameras acquired all the trappings of a fully-fledged computer in their own right, including full-fat operating systems and the accompanying hackability opportunities.

Prominent among camera manufacturers are Fujifilm, whose cameras it turns out have plenty of hacking possibilities. There’s something of a community about them, with all their work appearing in a GitHub repository, and a cracking April Fool in which a Fujifilm camera appears able to be coaxed into running DOOM.

Correction: We’ve since heard from creator [Daniel] who assures us that not only was the DOOM hack very much real, but that he’s released the instructions on how to run the classic shooter on your own Fujfilm X-A2.

Fujifilm cameras past 2017 or so run the ThreadX real-time operating system on a variety of ARM SoCs, with an SQLite data store for camera settings and some custom software controlling the camera hardware. The hackability comes through patching firmware updates, and aside from manipulating the built-in scripting language and accessing the SQLite database, can include code execution.

Don’t have a Fujifilm? They’re not the only hackable camera to be found.