DIY hologram projector

Using cheap items you may already have in your home, you can build your own 3D smartphone projector.

Technically, this simple DIY project doesn't produce a hologram, but the results look very similar. The idea is to create a pyramid of transparent, reflective material with the point facing down onto your smartphone screen. Using specially designed videos such as this one, the four sides of the pyramid reflect four identical animated images in a way that resembles a floating hologram.

This may have been inspired by the products marketed by 3D projector company Holho, but recently people have realized that it's super easy to just build one yourself. This instructional video from tech vlogger Mrwhosetheboss tells you all you need to know.This walkthrough went viral on Reddit over the weekend, leading to several helpful additions, including a printable pyramid template and a 3D projector-compatible version of Shia LaBeouf's "motivational speech" video.
All we need is for someone to create a YouTube template for Princess Leia's "Help me, Obi-Wan Kenobi" hologram clip, and your smartphone could become the perfect costume accessory this Halloween.