Spectral beam: Incandescent light bulb by Thomas Schielke / arclighting (Germany)

The foil in the spectral glasses breaks the light into its different visible electromagnetic waves. This transmissive optic creates a rainbow of colours. Wide rainbow patterns derive from a more diffuse light source whereas a narrow rainbow implies a brilliant one like LED or a low-voltage halogen lamp. http://www.youtube.com/watch?v=lWfMyAOyFbE