Hello!

I need some advice. I'm doing a two camera interview shoot. Both cameras are identical -- Sony Vixia HF21. I've already shot a few interviews with the cameras, thinking that since both cameras are identical make and model, my color balance would be accurate...or accurate "enough."

Wrong.

I set both to the same TUNGSTEN setting, but one camera produced a slightly more red coloration than the other.

Argh.

So I have a question.

First, in the future, I'm thinking I have to manually white balance both cameras against a white card. Easy enough. But, how is it best done? That is, each camera has its own position. Let's call them A and B. So...should I place both cameras in their respective positions and THEN white balance or should I, say, place camera 1 in position A, white balance, and then place camera 2 in position A, white balance, and then put one camera in position A and the other in B? Does that make sense? In other words, should both cameras be white balanced from the same spot before putting them in position?

I've always done a manual WB like this. I've got 2 cameras, one straight on to the subject and one to the left or right for about a 45 degree angle to the subject. My key light is to the same side as the 2nd camera and the fill is on the opposite side. Once I'm happy with the lighting I take a white card and place it where the subject would be sitting facing the A camera and WB that camera. I leave the white card where it is and WB the B camera. Yes the white card is facing the A camera but that's what the B camera is going to see and that's how it's lit. Will it 100% perfect? Maybe but even if it's not it will be a very easy fix in post if need be.
Is it the right way to do it? Got me but it's worked for me for 30+ years and so far I haven't had any complaints.
I'm sure others will chime in with their methods. None right, none wrong, just different. As long as the final product looks right that's all that matters. Remember a camera to one side or another from the subject is going to see the light differently, it's going to see shadows differently, it will probably see color a bit differently than the A camera. Just a fact of lite or life.

About a year ago, I started with a new procedure involving a portable calibration chart: Amazon.com: CowboyStudio Photo Studio 24 Inch Triangular Collapsible Balanced Reflector, Black/Grey/White and Silver: Camera & Photo (http://amzn.com/B001TC4UIG)

I'll white balance each camera under the main light source and include 5 seconds of the camera rolling while the chart fills the frame. This usually gets me 90% of the way, and is helpful when handing footage over to an outside editor.

If your pockets run deep, then a Chroma du Monde chart might help with that last 10% (color matrix, mostly).

Or, you can just do it the cowboy way: Set up your key (no other lights, especially mixed or other color temperatures). Bring both cameras around to the primary position, manually balance them on the same white card (or even better, one of Doug's WarmCards).

Move the cameras to their positions, and finish the backlight/background set up. Now, this assumes if you are doing an OTS shot of the reporter/interviewer, you are keying them with an identical color temp light fixture as the interview subject.