Programmable light stick with the Raspberry Pi Pico
Camera Settings
For an initial shot, I went outdoors in the evening, taking care to wear dark clothing. The camera was set up on a tripod a few meters away. With a short focal length, you can capture as much of the surroundings as possible. To have sufficient time for the shot, I set the exposure time to 20 seconds at a low ISO (not greater than 800, depending on the camera). Test shots helped me determine how much of the background could be captured with a chosen aperture setting. Depending on how much ambient light you have at dusk, the aperture can be f/8.0 or smaller.
If the camera's automatic focus doesn't work because of the low light level, a little trick helps: Focus on a bright object nearby; if necessary, shine a flashlight on it. Once you are confident, measure the distance and adjust the focus manually. In the end, with a little improvisation, the picture can be taken without an expensive camera system.
Some interesting light sequences are prepared in the source code of the project. The animations all run for about 15 seconds, so always a bit shorter than the exposure time. When shooting, it is important to move with as steady a hand as possible. For circular shots, the light stick offers a screw connection exactly in the middle. You can change everything, with nothing to limit your creativity (Figure 8). Compared with a static illuminated object, wherein only the same traces and patterns can be seen in the same image, this project shows its strengths. As far as favorable brightness and the timed sequence of LEDs are concerned, a targeted adjustment succeeds after only a few tests.
Conclusions
The Raspberry Pi light stick project has certainly not made me a light painting expert. Far more spectacular shots can be found online. However, combining my own interest in the Raspberry Pi and in photography gave me a lot of pleasure, and I still have a lot of fun designing new light images. Results from the Pi Pico toolset and MicroPython are completely satisfactory.
Infos
- Adafruit NeoPixel: https://www.adafruit.com/category/168
- Thonny: https://thonny.org
- Source code: https://github.com/swenae/lm_pico
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