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.

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 few questions.

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?

Next question: How in the world do I white balance in Kdenlive?! Like I said, the footage from one camera is a bit more red than the other. How do I make the footage from the "red" camera match the footage from the other?

First I'd check that both cameras have identical set up's via the menus, such as shooting profiles. Then I'd set the camera's in position, place a white or grey card in a position that both cameras see clearly and that get a decent representation of the light of the scene, then custom white balance both cameras. There will be those who say you should white balance the opposite way by putting a white cap on your lens and pointing them back towards the lighting falling on the scene but meh whatever, I'd be more concrened about getting some sort of consistency between cameras than total accuracy of the WB. Also may be useful to do a practice run and test cameras before the shoot.

Adjusting white balance after generating 8bit YCbCr in camera is a falacy, white balance is a function done before the raw data from the sensor is even interpolated so any color correction tool is appropriate to match clips once they are 8bit gamma applied video or imagery, combined with the Waveform Monitor and RGB Parade scopes to guide your adjustments.