UV and IR light can, literally and figuratively, show us the world in a totally different light. One of their common uses is to examine painting for authenticity or damage inspection. Sean Billups made his own tool for inspecting paintings, and it’s actually relatively simple.
Using an old Google Pixel 3a phone, a simple 3D-printed part, and lots of patience, he created a multispectral phone camera. By simply turning a small wheel, it reveals the secrets of any painting. And with some patience, you can also do it yourself.