Re: Green Screen with Z1U

I'll just add an alternative viewpoint to my friend Jeff's...

You have three levers to control the difference between the foreground and background:

-Saturation, the amount of color
-Hue, the phase of the color, and
-Luminance, the brightness of the color

You should try to create as much difference in each of these three factors to pull a decent color screen matte.

That also means that a background that is brighter than the foreground may be necessary where the foreground subject is dark...it will make controlling spill on the foreground critical...but it's the difference that is important, darker or brighter.

The guys at FX Guide recently tried pulling some keys in a test scenario with...I think a Viper, but I can't recall...and the background that was the brightest...well into a brightness where the saturation was being countered...keyed best. Not because overexposed green backgrounds work on everything...but it goes to show that a lower exposure isn't always the optimal approach.

Now...if the foreground you're shooting is bright green...that wouldn't work, but for this subject, I believe a blonde woman...that worked the best.

Use all three weapons available to you...and on green, lighting with daylight will also help (vs tungsten).




TimK,
Director, Consultant
Kolb Productions,

CPO, Digieffects