Github user Helge Wurst, known as MisterHW, has created an open-source, DIY LED ring light roughly the size of a credit card, making it a perfect pocketable companion for macro images on the go with your smartphone. The LEDCard not only provides an LED ring light but also incorporates an acrylic macro lens for capturing close-up shots without a specific macro function on your smartphone.

In its latest iteration, as outlined by Hackaday, Wurst's LEDCard is built 'using a single PCD with rechargeable lithium-ion coil cells (LIR2430) and a USB-powered charge controller.' When charged, the LEDCard lights up its built-in SMD LED lights with a single button press. You can control the intensity of the lights by half-pressing the power button for medium brightness or fully depressing the button for max brightness. There's also a 'test' button. Pressing this performs a battery level test.

In this first prototype of the LEDCard, Wurst accidentally flipped the photomask, but the long-term ideas were already in place, including a built-in macro lens and LEDs arranged in a ring around the lens. During this prototype, Wurst determined that the LEDs weren't quite efficient enough and the integrated battery lacked power.

While it's already a fully-functional design, Wurst has plans for future iterations. We spoke with him, and he says he's ordered new LEDs and improved lithium-ion cells for future revisions. Some people have offered feedback that a polarized light source and a more sophisticated achromatic lens element could improve the image quality. The latter concern is a big reason why the lens is replaceable, so users who may use the LEDCard themselves can opt for a different optical solution.

Another prototype introduced charging via USB and a medium brightness setting for the LEDs, although it still had some issues, including the risk of the li-ion cells deep discharging and being destroyed.

He believes that one of the most compelling aspects of the project isn't necessarily the result but rather the design process. Wurst said, 'As far as LEDCard is concerned, it occurred to me recently that the real value of the project lies in telling the story of iterative design and using it in everyday life until it breaks.' To that end, his decisions throughout the project, even minor ones, have been documented. Interested readers can opt-in to receive notifications whenever the project is updated. You can also follow Wurst on Twitter for more general musings on technology.

This version solved the battery issue and added a half-press function for the power button, although the button feel wasn't good enough.

Wurst built the LEDCard to solve a problem ā€“ the need to document electronic assemblies, defects and repairs without extensive gear and large lights. He's been an active hobby photographer since 2004, working with Canon DSLR cameras. However, in recent years, smartphone camera technology and performance have significantly improved, allowing him to bypass bulky camera setups and opt instead for a smartphone. It's convenient to have a camera that you can carry in your pocket, and its utility is enhanced significantly with a similarly compact LED ring light like LEDCard. As Wurst told us, it's nice to have extra lighting quality even when you weren't expecting to take any photos.

In this schematic, we can see the move to USB-C for charging. Wurst also designed this version (version E) of the LEDCard to accept three different lenses.

Beyond improved LEDs, a better power source, and better optics, Wurst is also an enthusiast of origami and compliant mechanisms, so some sort of pop-up reflector could be in the works. That'd be quite the handy accessory to carry around in your pocket, especially for mobile photographers who never know when an interesting shot may catch their eye.


Image credit: Helge Wurst (MisterHW). The LEDCard project is available under the CERN OHL-S v2 license.