How to depict light? Only in contrast with darkness. This was a fabulous experiment. I wrapped led christmas lights around a long stick, then set the camera on a long exposure and ran around the choir members making them laugh although they had to stand perfectly still.
That was a bit of a mistake though. No human can stand still for 20 seconds, even if there was nobody silly-running between them with a glowing stick. So I had to photoshop the blurry choir members out in the end. Luckily they were very satisfied with the result.