Chroma-key video, a.k.a. Green Screen, has come a long way since the 1970's local TV weatherman.
Today the Chroma-Key wall is employed in all kinds of ways to create compelling imagery. Even Hollywood has found new uses combining motion capture to create virtual sets. We often use our transportable "CK" wall when we either don't have a great spot to shoot in or if we have a lot of people to capture in a short period of time. So how does it work? You shoot the subject in front of a green screen, properly exposed and at the highest bit rate possible, then in the editing process, apply an effect that replaces everything that is bright green in the shot with a still or graphic image or video. So basically you can put your person anywhere! It's very effective and the result can be amazing! That is, if you know how to set everything up properly to achieve the best "key" or "clip" which is that contrast between the on-camera subject and the background.
It's really important to have a good understanding of lighting in this situation. The background must be lit independent of the subject. And when shooting multiple
different people on the same set-up, we like to make sure that we alternate the direction the talent faces. This way in the edited video, everyone isn't looking in the same direction. Often we even shoot with two cinema cameras at the same time. This way we get two alternating angles to cut between. We prefer this over the "punch in" method that many video pros utilize. Punching in digitally alternates between a close up and wider shot, but since the angle doesn't change, the effect isn't as desirable as shooting with two cameras.
There are many factors to consider when you and your video professional decide that a CK wall will suit your needs best:
Don't wear green - anything green will disappear in the shot
Anything reflective is best left at home
The frizzier the hair, the harder it is to get a clean "key" around the head.
Try not to talk with your hands too much, this can create motion artifacts.
Keep in mind you will need a lot of room for this set-up, or we may require a studio space to rent to shoot in.
That's really it! Just relax and have confidence that the boring green wall behind you will soon be an exciting landscape or a high tech office.
Green Screen shoots are not the best option for every shoot, but we have achieved some pretty remarkable results with them. It's also a great way for collaborative shots between multiple locations. If your company employs team members in different states, it's possible to shoot those individuals on Green Screen backgrounds and through the magic of video production, add in a background that brings it all together, on-brand
with a singular cohesive look.
