do you do this at the event?
Yes. If you read my blog you know I get to events very early. One of my steps when I put my cameras on the mat for setup is to do the CWB. My 1DMIII's allow me to preset five CWB settings so I don't actually have to do it each time. I always have a digital gray card in one of my Pelican cases so I just grab it and do the CWB by laying it on the mat usually shoving it under the ropes a bit although I could just as well climb into the ring and do it. There are also gadgets you can buy that go over your lens and you point them at the lights and take the necessary image but there are many other ways to use the gray card so I prefer it. If you just do it a few times you'll see it is trivial.






