A Much More DYI Air Gap Flash Unit

October 24, 2013 by Mathieu Stephan 38 Comments

In reaction to the other air gap flash unit we featured a few days ago, [Eirik] sent us a tip about another one he recently made. In his setup, the duration of the flash peak intensity is around 300ns (1/3,333,333 of a second). As a reminder, an air flash unit consists of a circuit charging a high voltage capacitor, a circuit triggering a discharge on demand, a high voltage capacitor and the air flash tube itself. The flash tube contains two wires which are separated just enough to not spark over at max potential. Isolated from the other two, a third wire is placed in the tube. This wire is connected to a trigger/pulse transformer, which will ionize the gap between the two capacitor leads. This causes the gap to breakdown and a spark to form, thereby creating a flash of light.

[Eirik] constructed his flash tube using an olive jar and a glass test tube. As you can see from the (very nice) picture above, the spark travels along the glass test tube, making the quenching much faster than in an open air spark. [Eirik] built his own high voltage capacitor, using seven rolled capacitors of roughly 2nF each made with duct-tape, tin foil and overhead transparencies. For ‘safety’ they are stored in a PP-pipe. A look at the schematics and overall circuit shown on the website reveals how skilled [Eirik] is, making us think that this is more a nice creation than a hack.

Disclaimer: As with the previous airgap flash, high voltages are used here, so don’t do this at home.

Making An Airgap Flash

October 22, 2013 by Mathieu Stephan 20 Comments

[Maurice] and his team just finished the airgap flash they’ve been working on for a year now. This kind of flash is useful for very high speed photography such as photographing shooting bullets. With a duration of about a millionth of a second it is 30 times faster the normal flashes at their fastest settings. In the video embedded after the break, [Maurice] first explains the differences between his flash and a conventional one which normally uses a xenon flash tube, then shows off different photos he made with his build.

Even though this video is a bit commercially oriented, [Maurice] will make another one detailing the insides. In the mean time, you can checkout the schematics in the user manual (PDF) and also have a look at an other write up he made which we covered in the past. We should also mention that trying to make this kind of flash in home is very dangerous as very high voltages are used (in this case, 16kV).

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BlenderDefender: Automating Pavlovian Conditioning

October 14, 2013 by Marsh 29 Comments

blenderDefender

This isn’t your typical home automation project; who turns a blender on remotely? [Brian Gaut] did, when he rigged his blender and a strobe light to scare his cat off the kitchen counter. To be fair, we’ve linked to this project before on Hackaday—twice actually—but neither the article about relays or the related cat waterwall article actually talk about the BlenderDefender, and that’s a shame, because it’s pretty clever.

[Brian] began by installing a DCS-900 network camera on the wall near his kitchen sink. The camera monitors any motion on the counter, and once it detects something, a networked computer starts recording individual frames. This security camera setup isn’t looking for criminals: [Brian] needed to keep his cat away from a particularly tasty plant. The motion detection signals an X10 Firecracker module to turn on both a nearby blender and a strobe light, provoking some hilarious reactions from the cat, all of which are captured by the camera.

Check out some other ways to work with the X10 firecracker, and feel free to jump into the home automation discussion from last week.

[Thanks Joy]

Perfect Jump Shots With OpenCV And Processing

October 13, 2013 by Adam Fabio 15 Comments

jumpshot

[ElectricSlim] likes taking “Jump Shots” – photographs where the subject is captured in midair. He’s created a novel method to catch the perfect moment with OpenCV and Processing. Anyone who has tried jump shot photography can tell you how frustrating it is. Even with an experienced photographer at the shutter, shots are as likely to miss that perfect moment as they are to catch it. This is even harder when you’re trying to take jump shots solo. Wireless shutter releases can work, but unless you have a DSLR, shutter lag can cause you to miss the mark.

[ElectricSlim] decided to put his programming skills to work on the problem. He wrote a Processing sketch using the OpenCV library. The sketch has a relatively simple logic path: “IF a face is detected within a bounding box AND the face is dropping in height THEN snap a picture” The system isn’t perfect, A person must be looking directly at the camera for the photo the face to be detected. However, it’s good enough to take some great shots. The software is also repeatable enough to make animations of various jump shots, as seen in [ElectricSlim’s] video.

We think this would be a great starting point for a trigger system. Use a webcam to determine when to shoot a picture. When the conditions pass, a trigger could be sent to a DSLR, resulting in a much higher quality frame than what most webcams can produce.

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Fail Of The Week: Photography Turntable

October 10, 2013 by Mike Szczys 28 Comments

Turntable photography has seen a rise in popularity driven by online shopping. If you can’t hold it in your hand at least you can see what it looks like from all angles. From the still image, [Petteri Aimonen’s] roll-your-own turntable looks great. It’s completely enclosed and has a very nice paint job. But when you see it in action it appears to suffer from a stutter.

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Game Controller Repurposed For Flea Market Find

September 30, 2013 by Marsh 2 Comments

powerPannerControlReplacement

A jarring pan with your tripod can ruin a shot in your film, and tilting up or down usually requires some loosening and tightening kung fu to keep gravity from taking over. The “Power Panner” is a remote-controlled device that fits between the tripod and the camera, handling pans and tilts with ease. When [NeXT] found one at the Capitol Flea Market for $5, he didn’t care about the missing remote. He bought the Panner, dragged it home, and hacked together his own remote with a Sega Master Pad.

After researching similar devices online, [NeXT] had determined the original remote’s pinout: essentially a D-pad with adjustable speed control. He decided to ignore the speed pins and to instead search for a suitable replacement controller. A Sega Master Pad offered the most straightforward solution, so [NeXT] went to work separating out the wires and soldering them to a DIN connector. He couldn’t find the right plug to fit the Panner’s DIN-7 jack, so he substituted a DIN-8 with the extra pin snapped off.

Rather than use the remaining two buttons for speed control, [NeXT] chose to feed them directly into his camera to drive the focus and shutter, but the Master Pad’s wiring posed a problem: the camera would have to share the Power Panner’s ground, and the Panner plugs into the wall via a 6V adapter. Fingers crossed, he decided to push ahead and was relieved that everything worked. We suspect the shared ground won’t be a problem as long as one device uses a floating power supply, which the Panner can provide either through the proper wall wart or by using its 4 AA battery option.

If you’re in the mood for more camera hacks, check out the sound-dampening and waterproofing build from last week.

Priceless Paintings – Scanned And Printed In 3D

September 24, 2013 by Phillip Ryals 25 Comments

When we think of works by Van Gogh and Rembrandt, most of us remember a picture, but we aren’t accustomed to seeing the actual painting. [Tim Zaman], a scientist at Delft University of Technology in the Netherlands, realized that the material presence of the paint conveys meaning as well. He wanted to create a lifelike reproduction in full dimension and color. While a common laser-based technique could have been used for depth mapping, resolution is dependent on the width of the line or dot, and the camera cannot capture color data simultaneously with this method. In his thesis, [Tim] goes into great detail on a hybrid imaging technique involving two cameras and a projector. He and his team eventually used two 40-megapixel Nikon cameras in conjunction with a fringe projector to capture a topographical map with in-plane resolution of 50 μm, and depth resolution of 9.2 μm.

We can’t find a lot of information on the printing process they used, other than references to high-resolution 3D printers by Océ (a Canon company). That said, [Tim] has provided a plethora of images of some of the reproductions, and we have to say they look amazing. The inclusion of depth information takes this a big step further than that gigapixel scanning setup we saw recently.

Check out the BBC interview with Tim, as well as time lapse videos of the scanning and printing process after the break.

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