Holographic Halloween: put on these spooky specs and bats will suddenly appear around every point source of light! The “lenses” in these glasses are actually transmission holograms but with the image located at the farthest point in the depth of field. Holograms involve the physics of diffraction- notice the bats from the purple lights are smaller, and that there is a bit of orange light in the spectrum of the purple LEDs. Made by @americanpaperoptics3d with many more images available for Hallow