Despite careful white balancing, footage sometimes ends up with an overall color cast or tint. This is often caused by mixed lighting or light reflected from colored walls, carpet and even clothing. But the colored surfaces that caused the color cast in the first place make it hard to eyeball a neutral color in the image. A quick and failsafe way to zero in on overall color cast without being distracted by colored objects in the image is to use a vectorscope display.
  • Before color correcting this kind of footage in After Effects, adjust the footage so that it’s neutral in color. This makes it easier to perform later color corrections because you’re starting from a known place, rather than fighting against the color cast.
  • Vectorscopes, like the one in Synthetic Aperturer’s Test Gear, display the neutral colors (blacks, grays, whites) at the center and highly saturated colors at the outer portions of the display. Most footage contains a mix of neutral and saturated colors. The different hues are represented by the position around the display, like the numbers on the face of a clock. Watch the vectorscope display as the footage plays. You’ll see a tight knot of pixels in the center of the vectorscope (the neutral colors) with various spikes of pixels radiating out from the center (the saturated colors). You can use Test Gear’s zoom feature to enlarge the central portion of the vectorscope to get a better look at the neutral colors.
  • If the image is neutral overall, the tight knot of pixels will be centered in the vectorscope display. If the central knot is shifted off-center, there’s a color cast. A shift toward the blue target on the vectorscope, for example, means there’s a blue cast to the image. To remove that, you need to move away from blue, toward yellow.
  • Depending on the color correction tool you’ve chosen, either remove blue or add yellow while watching the vectorscope display. When the central knot is centered on the vectorscope, you know you have a neutral image. No more color cast to worry about while you color correct.
– Bob Currier, Synthetic Aperture founder
www.synthetic-ap.com