Commercial version of the idea in this video can be found here:

I show a device that I built which lets you play light gun games even with modern TVs. I explain why light gun games don’t work on modern TVs and then show my solution. I show Duck Hunt on the NES, Virtua Cop on the Sega Saturn and House of the Dead 2 on Dreamcast.

Super long discussion thread:

Nintendo Zapper model by Cliche Studio
LED TV model by bistor
Nintendo Entertainment System textures by MatthewThorns