This effect is also known as Light Painting or Lumasol. It is inspired by the Ford Kuga promotion (video linked below). Tutorial is here: https://web.archive.org/web/20120412110340/http://kdenlive.org/users/granjow/writing-light-graffiti-effect
Light sources used:
— Test tube filled with water and a tiny bit of Fluorescein, lit by a blue laser pointer. Fluorescein then shines bright green/yellow. (First smiley.)
— A LED flashlight with a plastic straw, cut to 2" (5 cm), attached (white with blue stripes). (Paintings on the street, shovel)
— Fireworks called meteorite.
— A yoghurt cup, lit from the inside with the flashlight from above, and a colour gel attached to the LED. The colour gel was taken from a Rosco Swatchbook, linked below. (Last smiley)
I've written this video effect for the Open-Source video effect framework frei0r (linked below). It took me _ages_ to get the desired look, but now that it works I can release it to the public ;) The filter will very likely be available in your next version of kdenlive, OpenShot, etc.
Ford Kuga video by Tak+PIPS:LAB: http://www.youtube.com/watch?v=WVaxuIKPKvU
Rosco Swatchbook: http://rosco.com/sbreqs/index.cfm
If you wonder about the gear:
— The shots on the street were taken with a Canon 550D, 50mm f/1.8
— The rest was taken with a Nikon D90, 50mm f/1.8 and 35mm f/2.0.
This video was cut with kdenlive: http://kdenlive.org