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.
Here’s a completely non-invasive hack for a classic Minolta SLR camera. [Robby] wanted to add to the options available when it comes to remote shutter release. He ended up building a cable release add-on that mounts on the hot shoe.
He drew some of his inspiration from a similar project we saw back in March. He took the engineering example from that project which uses a small servo motor to actuate the cable release. But along the way added his own features.
The system centers around an ATtiny4313 microcontroller. It provides feedback using the character LCD on the back of the auxiliary flash body. That flash body also offers a battery compartment which provides power for the control circuitry as well as the servo motor. Right now it functions as a count-down timer, and also can hold the shutter a specified amount of time. But we could see this extended to work with external sensors to trigger at a set light level, when sensing motion, or from a remote control.
Odds are you played the game of Operation when you were a kid. The classic electronic toy challenges you to use a tethered tweezers to extract plastic pieces without touching the sides of the holes they’re hiding in. This upgrade makes the challenge more interesting for a grown-up audience. If you touch the sides you won’t hear a jarring sound, you’ll get a painful shock!
The modification starts by clipping off the melted plastic portions that hold the paperboard face plate on the game. From there the original electronics are completely removed. We think this a bit of a mistake as we’d still like spectators to hear the sound as the player gets a shock. But we digress. The circuit board from a disposable camera is patched into the game. A wrist band forms an electrical connection with your body, providing a path for the camera’s flash capacitor to discharge if you happen to touch the sides with the tweezers.
This write-up is missing one important thing: video of someone getting shocked. [Psycosisnine] promises to add some soon, but for now you’ll just have to fall back on our absolute favorite Mindflex shock project.
We don’t think this one is going to bring back the days of one-time-use flash bulbs. But for camera enthusiasts who do have old flash units lying around this will be quite interesting. [Sven] worked out a method of interfacing this vintage flash with a modern camera.
The trick is to map the trigger signal from the camera to the flash module. Instead of patching into an electrical signal from the camera he’s using the light from the stock flash. He cut an optocoupler in half, keeping the receiving side of the part. This is molded in plastic that was shaped to surround the original flash unit. When that flash goes off the triac in the remaining half of the IC is activated. This is connected to a hot shoe mounted on an extension arm that is attached to the camera’s tripod mount. The shoe can be used to interface a few different styles of flash modules.
We don’t have an alternative use in mind right now. But chopping an optocoupler in half could come in handy for other applications that use a bright light as a trigger event.
Continue reading “Adapting modern cameras to use old flash units”
The Dubjoy project was stopped dead in its tracks when the newest version of the Google Chrome browser stopped using Adobe’s flash plugin and transitioned to their own called Pepper Flash. The aim of development was to produce a browser-based editor for translating the audio track of a video clip. After a bit of head scratching and a lot of research they decided to try ditching the use of Flash and implemented a way to record audio using HTML5.
There were quite a few issues along the way. The initial recording technique generated raw audio files, which are not playable by Chrome’s HTML5 audio player. This can be worked around by buffering the raw audio, then converting it to a different format once the recording is finished. The user also needs to monkey with the Chromes flags to enable HTML5 audio. So they did get it working, but it’s not yet a smooth process.
We love seeing the neat stuff you can do with HTML5. One of our favorites is the use of a tablet’s accelerometer as a browser game controller.
Don’t get us wrong, we drive very carefully as it’s the most dangerous thing we do on a regular basis. But even a careful driver can get caught by bad traffic and a red light camera. These are devices that monitor intersections. If you get caught in the middle when the light goes red they take a picture and you get a ticket in the mail. Well, that’s the way it used to be. This traffic camera countermeasure puts it to an end. As you can see, the noPhoto uses a flash of its own to overexpose traffic camera images.
The image above shows the prototype. The foil is reflecting a flash on either side onto the license plate using a flash sensor which acts as the trigger. According to the demo video after the break, the system can even defeat the pre-flash, and dual-photo types of cameras.
There are pretty tight restrictions on using lights on your vehicles (colors, placement, etc.). We wonder if this passes muster?
Continue reading “Traffic camera countermeasure”
We never use the flash on our point-and-shoot. It has a way of washing out every image we take. But [Joey] has a different solution to the problem. He shows us how to make a papercraft flash reflector that will still light up your subject without washing out everything in the foreground.
[Joey] is perfectly aware that at first glance it would seem you need to have a reflective forehead for this to work. But the reflector is actually set up to aim the flash toward the ceiling. Since most ceilings are white this will reflect the light back into the room, dispersing it at the same time. His write-up includes a link to a PDF of the pattern. After cutting it out, one side is coated in black electrical tape, the other is left white to reflect the light. The design includes a tab that slides into the hot shoe of his Nikon DSLR to position it in front of the pop-up flash.