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Light painting is a photography trick that exploits a camera’s shutter. To ensure proper exposure in different lighting conditions, cameras have variable shutter speeds. If the subject is well-lit, then the shutter may only remain open for ten or so milliseconds. But if the subject is very dark, then a photographer may choose to leave the shutter open for minutes. Anything bright that moves in the frame will leave “painted” streaks. This project takes advantage of light painting to visualize magnetic fields.

Because exposure (both for film cameras and digital cameras) relies on brightness, anything dark that moves in a long exposure photo will be barely visible. But anything bright (LEDs, in this case) will be very visible. For this project, Chris Hill wears an LED array on their fingertip. When they capture a long exposure photo, their hand is dark and almost invisible. But the LEDs, which illuminate in response to the presence of magnetic fields, are bright and show up clearly in the picture. The result is a light painting of magnetic fields that would otherwise be invisible to the human eye.

The LEDs (an Adafruit NeoPixel Stick) and ultrahigh sensitivity analog sensor (to detect the strength of magnetic fields) are worn on the finger, but the rest of the electronic components reside in a 3D-printed enclosure that straps to the forearm. That enclosure contains an Arduino Nano 33 BLE board, an Adafruit MiniBoost 5V power module, and a 2500mAh LiPo battery. The Arduino monitors the strength of the magnetic fields detected by the sensor and then activates a proportional number of LEDs on the NeoPixel Stick. In the light-painted photo, this presents as a series of overlaid bar graphs that depict the magnetic field strength in their positions.

The post Use light painting to visualize magnetic fields appeared first on Arduino Blog.

Light painting has long graced the portfolios of long-exposure photographers, but high resolution isn’t usually possible when you’re light painting with human subjects.

This weekend project from [Timmo] uses an ESP8266-based microcontroller and an addressable WS2812-based LED strip to paint words or custom images in thin air. It’s actually based on the Pixelstick, a tool used by professional photographers for setting up animations and photorealism shots. The equipment needed for setting up the light painting sticks runs in the order of hundreds, not to mention the professional camera and lenses needed. Nevertheless, it’s a huge step up from waving around a flashlight with your friends.

The LED Lightpainter takes the Pixelstick a few notches lower for amateur photographers and hobbyists. It directly supports 24-bit BMP, with no conversion needed. Images are stored internally in Flash memory and are uploaded through a web interface. The settings for the number of LEDs, time for the image row, and STA/AP-mode for wireless connections are also set by the web interface. The project uses the Adafruit NeoPixel, ArduinoJson, and Bodmer’s TFT_HX8357 libraries for implementing the BMP drawing code, which also allows for an image preview prior to uploading the code to the microcontroller. Images are drawn from the bottom row to the top, so images have to be transformed before updating to the LED painter.

Some future improvements planned for the project include TFT/OLED support, rainbow or color gradient patterns in the LEDs, and accelerometer or gyroscope support for supporting animation.

There aren’t currently too many galleries of DIY LED-enabled light paintings, but we’d love to see some custom modded light painting approaches in the future.

This isn’t the first LED light stick we’ve seen, if you’re interested in such things.

Maker Jeremy S. Cook has experimented with both CNC machinery and light painting in the past, and decided to combine these two skills into a new artistic device. 

His setup uses a web app found here to program a CNC router as a sort of dot matrix printer. But instead of a pen, pencil, brush or other marking utensil, it uses a button as an input to the onboard Arduino Nano when pressed to the router’s surface.

From this input, the Arduino then commands a diffused RGB LED to “mark” the surface with light, painting an image on the camera’s exposed sensor. 

Code and print files are are available on GitHub if you’d like to try your own light art experiments!

Light painting: there’s something that never gets old about waving lights around in a long exposure photo. Whilst most light paintings are single shots, some artists painstakingly create frame-by-frame animations. This is pretty hard to do when moving a light around by hand: it’s mostly guesswork, as it’s difficult to see the results of your efforts until after the photo has been taken. But what if you could make the patterns really precise? What if you could model them in 3D?

[Josh Sheldon] has done just that, by creating a process which allows animations formed in Blender to be traced out in 3D as light paintings. An animation is created in Blender then each frame is automatically exported and traced out by an RGB LED on a 3D gantry. This project is the culmination of a lot of software, electronic and mechanical work, all coming together under tight tolerances, and [Josh]’s skill really shines.

The first step was to export the animations out of Blender. Thanks to its open source nature, Python Blender add-ons were written to create light paths and convert them into an efficient sequence that could be executed by the hardware. To accommodate smooth sliding camera movements during the animation, a motion controller add-on was also written.

The gantry which carried the main LED was hand-made. We’d have been tempted to buy a 3D printer and hack it for this purpose, but [Josh] did a fantastic job on the mechanical build, gaining a solidly constructed gantry with a large range. The driver electronics were also slickly executed, with custom rack-mount units created to integrate with the DragonFrame controller used for the animation.

The video ends on a call to action: due to moving out, [Josh] was unable to continue the project but has done much of the necessary legwork. We’d love to see this project continued, and it has been documented for anyone who wishes to do so. If you want to check out more of [Josh]’s work, we’ve previously written about that time he made an automatic hole puncher for music box spools.

Thanks for the tip, [Nick].

Light painting is an art form where dark areas are selectively lit to form interesting effects. While normally a manual operation, Josh Sheldon has come up with a rig to automate and enhance the process. The results are nothing short of spectacular, producing not static images, but astonishing animated light displays.

His device resembles a 3D printer made out of aluminum extrusion. X,Y, and Z axes are controlled by a series of stepper motors, but it uses a point of controlled light instead of melted plastic to form shapes. 

Light animations are set up in Blender, and a hardware and software toolchain including Processing, an Arduino Mega, and a Dragonframe module are implemented for control.

Check out the whole story in the video below, or see code/build documentation are available on GitHub.

Light painting is a technique which allows you to “draw” on a photograph by moving a light past the camera during a long exposure shot. While it can be difficult to master, light painting allows for some incredible effects such as text and images that appear to be hovering in mid-air. Think of it like a very slow but much cooler version of an augmented reality app.

[Reven] recently wrote in to tell us about the Arduino light painter he put together, and while DIY (and even commercial) light painting gear isn’t exactly new at this point, we think he’s raised the bar a bit with his design. With the addition of a slick 3D printed enclosure and on-board display and menu system, his light painter looks exceptionally professional for being built out of hardware he had on hand.

On his blog, [Reven] has done a phenomenal job of documenting the build from start to finish. Not only does he include a detailed Bill of Materials and the STL files so you can build your own version of his light painter, he walks the reader though his design process and explains why he did the things he did. Even if you aren’t interested in building a light painter, there’s almost certainly something of interest for anyone who’s ever looked at a pile of parts on their workbench and wondered how they were going to turn it into a functioning device.

Powered by an Arduino Uno, the light painter provides a user interface on a 16×2 LCD which allows control over not only the brightness of the WS2812 LED strips but selecting and loading different images from the micro SD card. The case was designed in FreeCAD, and while [Reven] mentions there are a number of issues which could be improved, satisfies all his design goals.

We covered the original Adafruit project that [Reven] based his code all the way back in 2013, though there’s certainly been more modern interpretations of the idea since then.

leds_cpaint_028Turn a Circuit Playground into a light-generating "paintbrush" for long-exposure photography.

Read more on MAKE

The post How to Easily Build a “Light Paintbrush” appeared first on Make: DIY Projects and Ideas for Makers.

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Finally, An Animated GIF Light Painter

animated gif, arduino hacks, GIF, led hacks, light painting, neopixel Commenti disabilitati su Finally, An Animated GIF Light Painter 

led_strips_dragon-flap

Light painting, or taking a picture of a moving RGB LED strip with a very long exposure, is the application du jour of Arduinos, photography, and bright, glowey, colorful things. Hackaday alumnus [Phil Burgess] has come up with the best tutorial for light painting we’ve seen. It’s such a good setup, it can be used to create animated .gifs using multiple camera exposures.

The build uses an Arduino Uno, SD card shield, and Adafruit’s new NeoPixel strip with 144 RGB LEDs per meter. Despite a potentially huge mess of wires for this project, [Phil] kept everything very, very neat. He’s using an Altoids case for the ‘duino, an 8 AA-cell battery holder and 3A UBEC  for the power, and a wooden frame made out of pine trim.

Part of the art of light painting involves a lot of luck, exponentially so if you’re trying to make a light painted animated .gif. To solve this problem, [Phil] came up with a very clever solution: using a rotary encoder attached to a bicycle. With the rotary encoder pressed up against the wheel of a bike, [Phil] can get a very precise measurement of where the light strip is along one dimension, to ensure the right pixels are lit up at the right time and in the right place.

It’s a wonderful build, and if Santa brings you some gift certificates to your favorite electronics retailer, we couldn’t think of a better way to bring animated .gifs into the real world.


Filed under: Arduino Hacks, led hacks


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