Expansion cloud chamber movie part 5 (Best and sharpest tracks yet)

Switched to a fixed focus on my camera (Sony Cyber-shot in movie mode) because the auto focus started to focus on the front of the class window. Added a magnifying glass in front of the camera to act as a poor man’s macro lens. This video shows how sharp the tracks can be. The radium paint coated pin is about 3/16 of an inch long.