Simple Photo Flash Trigger for Water Balloon Photography

Water Balloon Photography

There have been countless projects to make custom photo flash trigger circuits. Usually the circuits react to sound, triggering the camera flash at the moment a certain sound is triggered. That type of trigger can be used to detect the popping of a balloon or shattering of glass. Other triggers detect motion, like a projectile crossing a laser beam for example. [Udo’s] friend had a fun idea to take photos of water balloons popping. Unfortunately neither of those trigger methods would be well suited for this situation. That’s when [Udo] had to get creative.

[Udo] built a unique trigger circuit that uses the water inside the balloon as the trigger. The core component of the circuit is an Arduino. One of the Arduino’s analog pins is configured to enable the internal pull-up resistor. If nothing else is connected to the pin, the Arduino will read 5 volts there. The pin is connected to a needle on the end of a stick. There is a second needle on the same stick, just a short distance away from the first. When these needles pierce the balloon’s skin, the water inside allows for a brief moment of conductivity between the two pins. The voltage on the analog pin then drops slightly, and the Arduino can detect that the balloon has popped.

[Udo] already had a flash controller circuit. He was able to trigger it with the Arduino by simply trying the flash controller’s trigger pin to one of the Arduino’s pins. If the Arduino pulls the pin to ground, it closes the switch on the flash controller and the flash is triggered. Both circuits must share a common ground in order for this to work.

All of the code for [Udo’s] project is freely available. With such spectacular photographs, it’s only a matter of time before we see more of these floating around.

Reverse Engineering a Wireless Studio Lighting Remote

If you want to take a photograph with a professional look, proper lighting is going to be critical. [Richard] has been using a commercial lighting solution in his studio. His Lencarta UltraPro 300 studio strobes provide adequate lighting and also have the ability to have various settings adjusted remotely. A single remote can control different lights setting each to its own parameters. [Richard] likes to automate as much as possible in his studio, so he thought that maybe he would be able to reverse engineer the remote control so he can more easily control his lighting.

[Richard] started by opening up the remote and taking a look at the radio circuitry. He discovered the circuit uses a nRF24L01+ chip. He had previously picked up a couple of these on eBay, so his first thought was to just promiscuously snoop on the communications over the air. Unfortunately the chips can only listen in on up to six addresses at a time, and with a 40-bit address, this approach may have taken a while.

Not one to give up easily, [Richard] chose a new method of attack. First, he knew that the radio chip communicates to a master microcontroller via SPI. Second, he knew that the radio chip had no built-in memory. Therefore, the microcontroller must save the address in its own memory and then send it to the radio chip via the SPI bus. [Richard] figured if he could snoop on the SPI bus, he could find the address of the remote. With that information, he would be able to build another radio circuit to listen in over the air.

Using an Open Logic Sniffer, [Richard] was able to capture some of the SPI communications. Then, using the datasheet as a reference, he was able to isolate the communications that stored information int the radio chip’s address register. This same technique was used to decipher the radio channel. There was a bit more trial and error involved, as [Richard] later discovered that there were a few other important registers. He also discovered that the remote changed the address when actually transmitting data, so he had to update his receiver code to reflect this.

The receiver was built using another nRF24L01+ chip and an Arduino. Once the address and other registers were configured properly, [Richard’s] custom radio was able to pick up the radio commands being sent from the lighting remote. All [Richard] had to do at this point was press each button and record the communications data which resulted. The Arduino code for the receiver is available on the project page.

[Richard] took it an extra step and wrote his own library to talk to the flashes. He has made his library available on github for anyone who is interested.

Cheap Under-Cabinet Lights Reimagined as Photography Lighting

diy photography lights

Professional photography lighting can be expensive. Sometimes the professional photographer may not want (or need) to spend the big bucks on lighting. [Alex] is one of those folks. He needed a specialized light source and instead of going out and buying some, he made exactly what he needed out of components unlikely to be found in a photography studio.

The project started off with some off the shelf $12 Home Depot under-cabinet lights. Foam core board was attached to the sides of each light to adjust the beam’s width. Opening and closing these foam flaps allow the light beam to be adjusted to ensure the perfect shot.  The entire assembly was then taped to long, thin pieces of wood. The wood’s sole purpose is to facilitate mounting of the light.

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Lux: A 100% Open Source Camera


[Kevin Kadooka] recently finished his open source camera. The Lux Camera is 100% open source. Lux uses no parts from other cameras – not even a lens! To date we’ve only seen this with achieved with pinhole cameras. [Kevin] isn’t new to camera hacking. He was the man behind the Duo camera, which had a successful Kickstarter campaign in February of 2013. Duo is a DIY camera, but it still required lenses from Mamiya-Sekor, and a shutter from Seiko. Lux is a different animal. It has a manual focus 65mm f/5.6 Single Element lens. The shutter is [Kevin’s] own solenoid based leaf shutter design. Just as in the original shutter, an Arduino controls shutter operation and timing.

The main camera body and many of its parts are 3D printed. [Kevin] got some very nice quality parts from Shapeways 3D printing service. We have to say that some of the assemblies look a bit complex for desktop printers. However since everything is open source, anyone willing to put the time in could adapt them for the average RepRap or Ultimaker. [Kevin] has posted detailed build photos, as well as some photos taken with the Lux on his flickr stream. The pictures have  a decidedly holga-esque look to them, due in part to the single element lens. Even with this limitation, we love the idea of having a brownie style camera built completely from scratch.

Hackaday Links: January 12, 2014


[Kyle] teaches photography and after being dismayed at the shuttering of film and darkroom programs at schools the world over decided to create a resource for film photography. There’s a lot of cool stuff on here like mixing up a batch of Rodinal developer with Tylenol, lye, and sodium sulphite, and assessing flea market film cameras. There are more tutorials coming that will include setting up a dark room, developing prints, and playing around with large format cameras.

[hifatpeople] built a binary calculator out of LEGO® bricks or toys. It started off as a series of logic gates built out of LEGO® bricks or toys in the LEGO® Digital Designer. These logic gates were combined into half adders, the half adders combined into full adders, and the full adders combined into a huge plastic calculator. Unfortunately, buying the LEGO® bricks or toys necessary to turn this digital design into a physical model would cost about $1000 using the LEGO® Pick-A-Brick service. Does anyone have a ton of LEGO® Technic® bricks or toys sitting around? We’d love to see this built.

Think you need a PID controller and fancy electronics to do reflow soldering in a toaster oven? Not so, it seems. [Sivan] is just using a meter with a thermocouple, a kitchen timer, and a little bit of patience to reflow solder very easily.

The folks at DreamSourceLabs realized a lot of electronic test equipment – from oscilloscopes and logic analyzers to protocol and RF analyzers were all included a sampling circuit. They designed the DSLogic that puts a sampler and USB plug on one board, with a whole bunch of different tools connected to a pin header. It’s a pretty cool idea for a modular approach to test equipment.

Adafruit just released an iDevice game. It’s a resistor color code game and much more educational than Candy Crush. With a $0.99 coupon for the Adafruit store, it’s effectively free if you’re buying anything at Adafruit anytime soon. Check out the video and the awesome adorable component “muppets”.

Elinchrom EL-Skyport Triggered by Arduino

Screenshot 2013-12-25 08.39.33

[Toby] has an Elinchrom EL-Skyport, which is a wireless flash trigger. He decided to see if he could trigger it using an Arduino, and came up with a nice proof of concept. This little device was not meant to be user serviceable, as can be seen in what [Toby] uncovered while taking it apart. But once he had it disassembled, he cataloged everything inside, and then he awesomely went to the trouble of drawing up a schematic. With that knowledge, he began reverse engineering the SPI protocol used, which almost deserves an article by itself.

It was a long road to get there, but in the end [Toby] built a prototype Arduino shield that houses an nRF24L01+ module. These are very cheap to pick up on eBay. He gives us the details on hooking up the module, though he had to go through extra hoops since he was using the Arduino Leonardo. Still, once you’re up and running, you can make use of one of the existing libraries specifically for this module.

Thanks to his effort, the rest of us have one more device to hack on. Thanks [Toby]!

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Making an Airgap Flash

[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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