How to properly polarize studio lighting

Question

We've built out a small 3 camera video studio, but we have a big issue. On the wall we have a large TV used for presentations. We have 4 Flolight fluorescent light fixtures hung from the lighting truss on the ceiling. The problem that we have, (if you already haven't guessed it) is that we are catching the lighting in the TV screen reflection. The screen seems to have the anti-glare coating, so it's not glossy at all. The camera in the center that shoots straight onto it doesn't catch much of it, so that one isn't bad. However the side cameras catch all of it.

From digging around, I see that you can use a polarizer on the front of the lighting, and then a polarizer filter on the front of the camera lens. But my question is regarding what type of polarizers to purchase to properly remove the lighting in the screen.

Should both be circular, or both be linear?

How would I best hang the polarizer in front of the lighting fixtures?

Answer 1

Most flat panel LCD screens will not display properly if you place a polarizer filter in front of the camera lens. This is because the light from such screens is already polarized. That is why, with the advent of the "glass cockpit" made up of primarily LCD displays, pilot's sunglasses are no longer polarized.

Your best option is to set the lights high enough so that either the reflections off the LCD screen fall below the camera positions or so that you can place a flag between the lights and screen without blocking the subjects at the desk. Most commercial studios use the first option if they don't just use green screens and add the content from a second source via the control room.

Answer 2

If you want to show something displayed on the screen using your set-up, you will need a workaround. Usually, SFX for the wide-shot is called for and cheat the screen glare from each of the two individual guest waist-shots.

You have a choice of shooting green-screen on the monitor display area, carefully choosing camera angles to match monitor screen proportions and perspective; or to use a traveling matte for the monitor screen in post production.

If there is nothing to appear on the screen, you can cross-polarize the lights and the lens objective to mediate (but not eliminate) the glare.

You have a multiple-camera set-up. The angle of the polarizing screen(s) will vary with each camera-lighting set-up angle. There is no one-size fits all for the three cameras you want to use.

EDIT: The easiest way to include the smartboard during recording is to position the middle (wide-shot) camera so there is no glare. Oblique (off-axis) lighting will help mitigate the glare. You might not need any polarization if the camera and smartboard are placed facing each other (perpendicular) on-axis. Use with the off-axis lighting in a "copy stand" kind of lighting to reduce glare.

Use the outboard supplementary cameras in cross-shots for individual MCUs of the two participants for commentary and reactions. Avoid showing the smartboard with either of them to avoid the inherent glare from the matte screen and diffuse luminaries.

EDIT 2: To answer your question about polarizing material. Use linear with the axis perpendicular to the plane of polarization. The plane is vertical so you would position the axis of polarization horizontally. The glare will not be eliminated as the surface of the screen is textured so specular highlights will not be affected.