To show and then play a movie, click on the arrow or the movie title/description. Repeat to hide it.

UL L1 Movie 1: Pinhole and one light source (Maglite™): Moving the light source

UL L1 Movie 2: Pinhole and two light sources (Maglites™)

UL L1 Movie 3: Pinhole and one long, continuous light source

UL L1 Movie 4: Shadows: Maglite™, rectangular blocker, and screen