Quite often we are asked to assist with green screen shoots on location and in studios.  This month we are highlighting some of the special techniques and equipment we use to increase your familiarity with these approaches, when you contact us for your next green screen shoot.

As you probably know it is best to light the green screen as flatly and evenly as possible with no color or tone variations.  One thing that you need to begin with is a material that is smooth and taught so that there are no shadows. We recommend exposing the screen below the subjects key lighting, but not more than a full stop under.  Conversely, the subject lighting does not need to be flat and can be done in any manner befitting the final composite.  This is the most enjoyable part of green screen work, so bring along examples of the final background if you have them and show them to your Gaffer.

In order to minimize the  green spill on the subject or unnatural shadows falling on the screen It is important to keep the subject as far away from the screen as possible. This also makes separating the lighting schemes easier.  A larger room is better since you're going to be using more space with a larger screen.. One of our most recent projects for Microsoft was in a large room, but it did not have high ceilings.  A 6'x6' or an 8'x8' green screen would have worked, but we wanted the subject as far away from the screen as possible to avoid green spill.  Since a camera's aspect ratio is wider than it is taller we can make sure that as we moved the camera back we wouldn't loose the green screen on either side of the frame.  We decided to use our 12'x12'/6'x6' breakdown frame.  We put the frame together in a 12'x6' configuration and attached the 12'x12' green screen to the frame folding the excess under and around the frame and tying it off to the other side.  We made sure to stretch the green screen tight to remove all wrinkles.   The Result: A 12'x6' green screen wide enough to stretch across the room but short enough to fit below the ceiling.   This also allowed us to place the subject further away from the green screen.

Also you can limit the spill and bounce of the screen by setting some flags and cutters behind the lights and as close to the green screen at the final edge of frame between talent and green screen. One handy tool for this is the 3x3 drop floppy made by American Grip Inc.  the 3x3 is a handier size than a normal 4x4 floppy for these locations and when unfurled covers a whole 18 Square feet.

Instead of using tungsten hot lights, we decided to use our Kino Flo's with Super Green lamps.  These fluorescent tubes are designed specifically for lighting green screens. Below is an excerpt from Kino Flos' own website highlighting the features of the lightweight cool and color specific systems. 

Kino Flo's operating Super Green lamps are inherently superior in lighting quality to any source when lighting painted cycs or green screens because:

* Super Green lamps emit a pure green light (560 nanometer spike). There is almost no contamination of the adjacent colors.
* Kino Flo's put out 10 times as much light per watt as tungsten sources.
* Kino Flo's are a lot cooler and have a softer, more even beam spread.
* Kino Flo's can control light levels without a change in color temperature.