Lighting a Green Screen
In case you're wondering, the green screen does require it's own lighting. It's highly unlikely that you would be able to use the screen with existing ambient light or the same light you use for the foreground subjects. As mentioned previously, you should plan your screen lights before you begin construction.
The key to lighting a green screen is consistency. The whole point is to create a single, consistent shade of colour across the entire screen.
You will need at least two lights, preferably more. The diagram below shows how you could light a green screen which is a few metres across, using a couple of 300-500w lights (one at each end) and a couple of 100-250w lights below pointing up.
Note: Diffusion filters are very handy when lighting green screens. Diffusion helps create more even lighting and reduce the impact of shadows.
You will probably want to experiment with different combinations to get the most even lighting.
Once the screen is lit to your satisfaction, add the main lighting for the subjects. At this point you may find that shadows created by these new lights are cast on the screen. Adjust the light positions and filters until you get the best compromise.
Next Page: Using Green Screen Footage