Sometimes when we shoot with our XL2 the white balance will shift all on it's own as we shoot. For example, recently we were doing a shoot inside with halogen lights and the XL2 set to the indoor white balance setting. As we shot it shifted back and forth from cool to warm. We've also had this happen with our XL1S cameras. Anybody know what's going on?

Not sure of the reason for this, but if you shoot with a fixed shutter speed (Tv mode) it doesn't happen.

Richard

Also be sure that Gain is not set to Auto, as that can affect WB.

So I take it you guys have had the white balance shift like that for you too?

The XL2 was in Manual mode with the gain set to 0; so once a take started, the gain and shutter speed stayed consistent and yet the white balance still shifted a lot.

Had this same problem before. How I fixed it.

1. Don't shoot with auto settings.

2. Make sure all your lighting is the same temp.

If there is a flourescent light anywhere close and you are lighting with halogens then look out here comes the shifting.

You mentioned Halogen lights. They are the seed of the problem. I have seen the same thing when shooting in a Hockey Arena with white set to preset.
The halogens are phasing out of sync with the shutter of the camera. Try setting your shutter speed to 1/60 and see if it solves the problem.

I'll look up a better technical explanation and get back to you.

OK. Here's some info that might shed some light on the phenomenon.

http://www.cinematography.net/Pages%20DW/ColorPhasing-FluoroLightF900.htm

Thanks for the link Tim. It happened to me in an office interview shoot where there were both fluorescent strip lights and halogen downlights. When moving the camera around I noticed a blue colour shift even though I had set a manual WB. Setting the shutter to 1/50s cured it (I am in PALland).

Richard