Xiaomi Yi Lens Filter

This is a lens filter assembly that I made for the Xiaomi Yi camera. It prints in three separate printer-friendly pieces that must be glues together. A filter of your choice (ND, polarizer) is inserted between the main housing and top ring.

The size of this filter allows the use of the Yi's complete 120 degree field of view without having any vignetting on the image. It is just about as wide as the Yi is tall so the camera will still sit upright on a flat surface.

I decided to make my own filter after not finding a suitable one online. The filters I found for sale were said to add vignetting to the video, and the ones that were large enough to avoid this issue would take weeks to arrive. So I made my own design and used the polarized lens from an old pair of 3D movie glasses.