an easily tell the difference in the hues. It is becoming more common to see the other two video colors red and green being used where the subject matter requires it.Lighting is difficult with chroma-key and Ultimatte. Great care must be taken to make sure that the blue, red, or green backdrop is very evenly lit with no shadows or highlights basically flat. However the subject may be lit any way that you choose. Ultimatte keyers have very fine controls that allow for exacting adjustment of the way that the background image will be composited. This can sometimes make up for subtle defects or shadows in the blue screen. A waveform monitor is standard equipment in a blue screen video shoot because it gives a graphical representation of video levels in a scene. Small inconsistencies in the video levels become very obvious when viewed through the waiveform monitor. A spot light meter will not give you the consistent results required for blue screen compositing. So the next time you see people hanging off of a cliff in a commercial or watch your nightly news. You will have a greater understanding of just what it takes to accomplish such stunning visual illusions....
