Applied Learning Technologies Institute, Arizona State University

The Process

The first step, and probably the most important, is lighting. Good lighting will go a long way in making the whole process a lot less painful. After doing some research from people who have a lot more experience than us in this technique, here are some lighting rules to live by:

• light the subject with soft light source (kinoflo, or use a diffusion panel)
• create a fair amount of distance between the subject and the blue/green background (minimize bounce back color from blue/green background)
• the background should be evenly lit and as seamless as possible a backlight is critical in helping to eliminate bounce back light from the blue/green background (just in case you didnt have enough distance from the background)

Once the footage is shot and digitized, we import the selected files into After Effects for final compositing. The key element in After Effects is a third-party plug-in from Ultimatte. Not cheap, but well worth it if you want a clean composite. It has a frightening amount a parameters to tweak, but once you get a handle on it, it just works!

In After Effects, you have 3 layers to deal with, the foreground (top), background image (middle), and what Ultimatte calls the Screen Correction layer, which compensates for any light anomolies (excessive highlights and shadows). It's a layer that's a representative color of the blue/green screen.

In this example, our goal was to place our subject (a genetics professor) in Darwin's office. We scanned a photo of Darwin's actual office, tried to dress the professor up in the appropriate period attire, and shot him in front of a bluescreen.

First, the magical Ultimatte filter was applied, and with some minor tweaking, the blue background was gone. Then the color saturation of the subject was eliminated and the final composite was then treated with another third-party filter called Aged Film. Our non-linear editor was able to add a bit of sepia tone to it for the finishing touch.

A final note on lighting. When we lit our subject, we had already chosen and scanned the background image of Darwin's office, and tried to emulate the lighting as if our subject was in the office. It helped in adding a sense of realism to the final composite.

(View a sample clip from the resulting movie)

View a sample clip
from the resulting movie

Studio Setup