This Camera Captures Piezo Inkjet Micro-Drops For DIY Microfluidics

April 15, 2020 by Donald Papp 6 Comments

In microfluidics, there are “drop on demand” instruments to precisely deposit extremely small volumes (pico- or nano-liters) of fluid. These devices are prohibitively expensive, so [Kyle] set out to design a system using hobbyist-level parts for under $1000. As part of this, he has a fascinating use case for a specialized camera: capturing the formation and shape of a micro-drop as it is made.

There are so many different parts to this effort that it’s all worth a read, but the two big design elements come down to:

Making the microdrop using a piezo element
Ensuring the drop is made correctly, and visually troubleshooting

Working prototype. The piezo tube is inside the blue piece at the top. The camera is to the right, and the LED strobe is on the left.

It’s one thing to make an inkjet element in a printer work, but it’s quite another to make a piezoelectric element dispense arbitrary liquids in a controlled, repeatable, and predictable way. Because piezoelectric elements force liquid out with a mechanical motion, different liquids require different drive signals and that kind of experimentation requires a way to see what is going on, hence the need for a drop observation camera.

[Kyle] ended up taking the lens assembly from a cheap USB microscope and mating it to his Korukesu C1 USB Camera with a 3D printed assembly. Another 3D printed enclosure doubles as a lightbox, holding the piezo tube in the center with the LED strobe and camera on opposite sides. The whole assembly had a few false starts, but in the end [Kyle] seems pretty happy with his results. The device is briefly described at a high level here. There are some rough edges, but it’s a working system.

Inkjet technology has been around for a long time (you can see a thirty-plus year old inkjet printer in action here) but it’s worth mentioning that not all inkjet heads are alike. Most inkjet printer heads operate thermally, which means a flash of heat vaporizes some ink to expel a micro-drop. These heads aren’t very suitable for microfluidics because not only do they rely on vaporizing the liquid, but they also don’t work well with anything other than the ink they’re designed for. Piezoelectric print heads are less common, but are more suited to the kind of work [Kyle] is doing.

8mm Film Scanner Grows Into A Masterpiece

April 12, 2020 by Mike Szczys 73 Comments

Digitizing film is a tedious process that becomes a lot more fun if you spend more of your time building a digitizer and less time actually working working with old film. [Heikki Hietala] has been at it for years and his Kotokino Mark IV film scanner is a masterpiece of simple machine building.

Since we first saw the film scanner four years ago it’s undergone a number of excellent improvements. Most notably, the point-and-shoot camera has been swapped out for a DSLR. With the use of a macro reversing ring a normal lens is flipped around to blow up the 8-millimeter-wide film to take advantage of all the megapixels available on the camera sensor.

The key to the setup is the film advancer mechanism which takes care of both advancing the film and triggering the camera. As you can see, a servo motor rotating an axle provides the locomotion. The mechanism keys into the perforations in the film to pull it along on the down stroke and closes a switch to trigger the camera on the upstroke. Directly under the lens, the alignment jig uses lens cleaning fabric to avoid scratching the film, while perfectly positioning it over the light source.

Previous versions have placed the camera on the horizontal plane but it seems some vibrations in the system caused alignment problems between captured frames. This latest version places the camera pointed straight down to solve that issue, and brings the entire thing together into one beautiful finished project. Having gathered numerous fans of the build along the way, [Heikki] has made the design files available so that you may build your own version.

Classic Leica Film Camera Turns Digital

April 10, 2020 by Bryan Cockfield 36 Comments

While there’s still a market for older analog devices such as vinyl records, clocks, and vacuum-tube-powered radio transmitters, a large fraction of these things have become largely digital over the years. There is a certain feel to older devices though which some prefer over their newer, digital counterparts. This is true of the camera world as well, where some still take pictures on film and develop in darkrooms, but if this is too much of a hassle, yet you still appreciate older analog cameras, then this Leica film camera converted to digital might just attract your focus.

This modification comes in two varieties for users with slightly different preferences. One uses a Sony NEX-5 sensor which clips onto the camera and preserves almost all of the inner workings, and the aesthetic, of the original. This sensor isn’t full-frame though, so if that’s a requirement the second option is one with an A7 sensor which requires extensive camera modification (but still preserves the original rangefinder, an almost $700 part even today). Each one has taken care of all of the new digital workings without a screen, with the original film advance, shutters, and other HIDs of their time modified for the new digital world.

The finish of these cameras is exceptional, with every detail considered. The plans aren’t open source, but we have a hard time taking issue with that for the artistry this particular build. This is a modification done to a lot of cameras, but seldom with so much attention paid to the “feel” of the original camera.

Thanks to [Johannes] for the tip!

That Retro Video Look, Without The Tapes

March 7, 2020 by Jenny List 11 Comments

We’re lucky to live in an age of rapid technological advancement, lucky in more ways than one because as well as receiving a constant supply of new things, we have the benefit of the older tech that once we lusted over, at knock-down prices. [Luke Baker] spent his youth as a skateboarder, and the cameras of desire in that community were the high-end MiniDV models. They may not have high definition but their output has a Millennial aesthetic that captures the period, so he’s brought one into the 2020s by adding a digital SD card recorder designed for a multirotor to it.

On the face of it this is a pretty straightforward job of coupling an off-the-shelf recorder to a battery and the camera’s analogue output terminals. But the resulting spaghetti on what is supposed to be a portable device is hardly attractive, so he’s created an all-in-one 3D-printed enclosure that is attached to the camera’s handle with a set of cable ties. It’s shaped to fit the recorder and has a sliding lid over the battery compartment, and he’s added a handy on-off switch. Whether or not he takes it to the skate park in a bid to roll back the decades, as you can see int he video below the break it’s a well-executed piece of work that should serve to remind that there’s still life in some of this easily-available old tech if you’re prepared for a bit of lateral thinking.

This isn’t the first vintage video hack we’ve seen, back in 2016 we were treated to the grainy period feel of a vintage 8mm camera through the eye of a Raspberry Pi.

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Camera And Code Team Up To Make Impossible Hovering Laser Effect

March 5, 2020 by Dan Maloney 20 Comments

Right off the bat, we’ll say that this video showing a laser beam stopping in mid-air is nothing but a camera trick. But it’s the trick that’s the hack, and you’ve got to admit that it looks really cool.

It starts with the [Tom Scott] video, the first one after the break. [Tom] is great at presenting fascinating topics in a polished and engaging way, and he certainly does that here. In a darkened room, a begoggled [Tom] poses with what appears to be a slow-moving beam of light, similar to a million sci-fi movies where laser weapons always seem to disregard the laws of physics. He even manages to pull a [Kylo Ren] on the slo-mo photons with a “Force Stop” as well as a slightly awkward Matrix-style bullet-time shot. It’s entertaining stuff, and the effect is all courtesy of the rolling shutter effect. The laser beam is rapidly modulated in sync with the camera’s shutter, and with the camera turned 90 degrees, the effect is to slow down or even stop the beam.

The tricky part of the hack is the laser stuff, which is the handiwork of [Seb Lee-Delisle]. The second video below goes into detail on his end of the effect. We’ve seen [Seb]’s work before, with a giant laser Asteroids game and a trick NES laser blaster that rivals this effect.

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A Minimal ESP8266 Digital Picture Frame

March 1, 2020 by Tom Nardi 2 Comments

Over the last few years, the price of a good digital picture frame has dropped to the point that we don’t often see DIY versions anymore. As much as we might hate to admit it, it’s hard to justify building something yourself when the economies of scale have made it so you can buy the final product for less than the cost of the parts themselves. But of course, there are always fringe cases where building it might be the only way to get what you need.

Granted we’re not sure that [Tony Liu] actually needs a 1.8-inch digital picture frame, but we’re sure somebody out there does. The ST7735R display used in this project is a real TFT, so the color and refresh rate is pretty good; but with a resolution of just 128×160, we’d recommend keeping your expectations low in regards to visual fidelity.

What’s really interesting about this project is how low the part count is. All you need is the ST7735R display and the ESP8266 itself (or the development board of your choice, naturally). Even the 3D printed frame is technically optional. The display is driven by SPI, so with the power added in, that’s only eight wires that need to be soldered between the two devices. If you’re looking for an easy way to add a photo slideshow to a small device, say a conference badge, this is about as easy as it gets.

But where are the images coming from? You might think SPIFFS, but in this case [Tony] has converted the images to bitmaps and is loading them into the Arduino Sketch as a header file with PROGMEM. Helpfully, he provides the link for the tool he uses to convert the images into an array the graphics library can understand. This makes adding new images slightly time consuming, but we imagine if you have the need for something like this, it’s probably only showing a pretty specific set of images anyway.

If you’re looking for something bigger, or maybe just an excuse to put that dusty Raspberry Pi to use, you might be interested in one of the more substantial builds we’ve seen over the years.

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Building Cameras For The Immersive Future

February 28, 2020 by Lewin Day 6 Comments

Thus far, the vast majority of human photographic output has been two-dimensional. 3D displays have come and gone in various forms over the years, but as technology progresses, we’re beginning to see more and more immersive display technologies. Of course, to use these displays requires content, and capturing that content in three dimensions requires special tools and techniques. Kim Pimmel came down to Hackaday Superconference to give us a talk on the current state of the art in advanced AR and VR camera technologies.

[Kim]’s interest in light painting techniques explored volumetric as well as 2D concepts.

Kim has plenty of experience with advanced displays, with an impressive resume in the field. Having worked on Microsoft’s Holo Lens, he now leads Adobe’s Aero project, an AR app aimed at creatives. Kim’s journey began at a young age, first experimenting with his family’s Yashica 35mm camera, where he discovered a love for capturing images. Over the years, he experimented with a wide variety of gear, receiving a Canon DSLR from his wife as a gift, and later tinkering with the Stereorealist 35mm 3D camera. The latter led to Kim’s growing obsession with three-dimensional capture techniques.

Through his work in the field of AR and VR displays, Kim became familiar with the combination of the Ricoh Theta S 360 degree camera and the Oculus Rift headset. This allowed users to essentially sit inside a photo sphere, and see the image around them in three dimensions. While this was compelling, [Kim] noted that a lot of 360 degree content has issues with framing. There’s no way to guide the observer towards the part of the image you want them to see.

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