A Real Lighthouse Light
For the first five minutes, they hold the lens stationary so that all the photographers "can take their digital masterpieces before processing them on the computer in PhotoShop" (so said the announcer). After the first five minutes, they let the lens rotate at its normal speed.
This is exactly what it looked like during the first five minutes. No star-effect filter, and no PhotoShop tricks. I never realized that a real lighthouse light was a collection of multiple beams. This was necessary because they couldn't make the huge lenses rotate very fast with the old machinery.
Despite my heroic efforts to bracket adequately within the five minute window, this shot (the brightest of the bunch) was still underexposed, so it's a bit grainy.
Thanks to Roland Ruehl for letting me know about this event.