FORUMS: list search recent posts

Re: Green Screen

COW Forums : Corporate Video

Respond to this post   •   Return to posts index   •   Read entire thread

Colter Ripley
Re: Green Screen
on Apr 21, 2010 at 9:10:05 am

Here's an excerpt from one of the tutorials that I've written for doing green screen videos. This is how I do it for some of my clients. Hope this can help.

"First of all, I will assume you have some lights, a green-screen and a camera. The rest of this tutorial will be about arranging them.

Now if you don't already know, chroma green is a certain color that works well with cameras. You ever heard of a 4:2:2 color space? How about RGB? Well without making things complicated, most color information is stored in the Green space of the color channel (G) on your digital camera. So make sure that green-screen is the appropriate color.

1. First off: Lights

Lights are THE MOST IMPORTANT aspect of getting great quality separation of your subject from the green-screen - and ultimately - a good key. And when I say key, I mean when you bring the footage into your editing software, your subject separates well from the background.

This is what separates the pros from the amateur.

You can have the best acting, the greatest cameras, and the best crew but if you don't successfully create this separation... Your green-screen will have those nice green edges, reducing realism.

No down to the details.

2. Use a back light

When I say this, I mean a light that illuminates the back of your subject. Sometimes this light is higher in the air, sometimes lower (I recommend about 20% higher than your subject) but it is ALWAYS pointing at the back of your subject (in between your subject and the green-screen). Put that light on a 45 degree angle. Getting one light per side (same angle, same height) is ideal.

So what does this do? Well it creates a subtle white "halo" around the edges of your subject. Like a small white or illuminated edge, it's going to dramatically affect the quality of your key.

3. Light the Green-screen

I want to look at the green-screen and see an even covering of light. No wrinkles, no brighter parts, no shadows, perfect, even and green.

4. Choosing Lights

Ways of lighting that green-screen? A light on either side. Overheads and floor lights. They make Cyc lighting that casts an even light from the floor up (rent these from your local gear rental shop).

I use a four bank KinoFlo on either side of the screen depending on how much you expect the subject to move."



Posts IndexRead Thread 

Current Message Thread:

© 2019 All Rights Reserved