I wanted to see if I could detect the radiation from a small sample of americium-241 that I pulled out of a smoke detector, so I put a Pi camera with no lens facing it and took exposures for a couple hours. After combining them and removing dead pixels I ended up with tons of tiny white specks where radiation had hit the camera sensor. I linked the final image below, and here's a timelapse video (compositing newer frames onto older frames to keep the radiation specks). video