This converts the IKEA Knäred led torch into a pinhole projector making it a nice childrens night light.
The idea is that an ideal point light source can project a sharp image without using optics for focusing. This is not very efficient because most of the light is blocked behind the pinhole, resulting in a pretty dark image. It still works reasonably well in a dark room.
The hole size and the alignment with the led affect the projection quality. It is not a perfect point light source, so the projection gets a bit blurry a farther distances.
The Knäred torch is nice little hackable light. I originally had this idea in 2016 when I first got one, now I finally got around creating it. Unfortunately it seems it is no longer sold by Ikea.
Made the disks slightly thicker and less flexible, so it is easier to snap them into place.
A collection of additional projection disks is available here!
- Should be printed with black filament to minimize reflections inside the cone.
- Supports must be enabled, but it is very easy to remove.
- A "blank" projection template is included to punch out your own designs.