Check Out Ivan Miranda’s Huge Long-Exposure “Light Painting” LED Display

A long-exposure display is kind of like a persistence of vision (POV) display, but for cameras. A normal POV display has to move very quickly, because your eyes have a short “exposure” time. Cameras, however, have adjustable exposure times, which is how long you leave the shutter open. With that in mind, a relatively slow-moving light source can become a single image if you use a long exposure. That’s exactly how Ivan Miranda’s new LED display works, just on a massive scale.

Creating this kind of long-exposure image is usually referred to as “light painting,” and this project does that painting programmatically. The frame for Miranda’s display was constructed from a combination of 3D-printed parts (in the usual red color, of course) and aluminum extrusion tubes. That results in a display that is a crazy three meters tall (almost 10 feet). The lights are a strip of WS2812B NeoPixel-style individually-addressable RGB LEDs, which are controlled by a Teensy 3.6.

After putting together a power supply that could handle the substantial load of the LEDs, Miranda used the Arduino IDE to upload a program to convert images into long-exposure times for the LEDs. The program turns each vertical line of the image into instructions for the LEDs, and the switches to the next line a second or so later. With the lights off, Miranda moved the display by hand across the room. When the camera is setup for a long exposure, a solid light-painted image appears!