I just spent several days coming up with a method to match the subject cameras under mixed and varying light sources in an ice rink. The show started while the sun was up and two doors allowed this external light into the mix. There are fluorescent fixtures along the walls and some kind of mercury fixtures over the ice. By the end of the ~2 hour show the sun had set so no external light was in play.
The XHA1 was on one end of the rink, panning from an entrance door on the long wall and widening to a shot of the expanse of ice. The HFG10 was in the middle door, panning from side (door light merc mix) to center (fluorescent and mercury mix) to far left with a door spilling onto the ice and overhead mercs.
We manually white balanced off the ice with each camera but this was essentially unusable without further correction. Key indicators are the color of the ice and the synchronized skating costumes which should look the same on each camera. A yellow stripe runs along the bottom of the kick boards in this hockey rink and the XHA1 represented this as orange. The HFG10 showed it as greenish yellow as did the HV40. The output is an MPEG2 file rendered by Vegas from the DVD Architect NTSC 16:9 template.
The best matching in Sony Vegas Pro 10 was with the AAV Colorlab plug. It allows the yellow stripe to be matched as one of the six color controls in addition to picking white. The render time for 48 minutes of video was around 90 minutes. The initial trial software I used was the FBmn Software white balance plug, which I was not able to successfully adjust costume color on and took nearly 4 hours to render the 48 minute Act 2 segment (guessing that it couldn't use my GPU).
For 2012 I hope to migrate to FCPX so I didn't want to sink a lot of money into additional Vegas/Windows product. If FCPX isn't ready to do 3-cam edits, I may have to do this at least one more time in Vegas. I have a license of Vegas Pro 11 but am not confident enough about its stability to upgrade right now.
Sorry for the long post. If anyone has dealt with this in a rink, I'd love to hear ideas on better, cheaper or more efficient methods to match colors. We usually don't walk onto the ice with white cards or color charts but this probably could be arranged if it aids in post production color matching.
Thanks in advance and happy new year!