User`s guide

Using the Shot Editor
Shot Editor Chroma Key
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Wirecast User Guide | 104730
White Clip
Likewise, white areas are also sometimes keyed out when they should not be. The
White Clip parameter controls how close the keying is toward white. For example, if the
host has a white shirt on, you need to increase this value slightly so that the keying
effect is not seen in his shirt. Adjust the White Clip (0 to 100) by using the slider.
Getting a Good Key
Probably the most important part of getting a good key is getting good source
material. Poor source material generates poor keys; no algorithm can make up for this.
Lighting
Assuming you have a reasonably good camera, the most important part of getting a
good key is good lighting. Invest in good lights and learn how to set them up properly.
Here are some basics:
• The background screen (green or blue) needs to be independently lit from other
items in the shot.
• Light the background screen evenly, with no shadows. The more evenly lit, the bet-
ter the keying.
• Light people evenly with no shadows. A fill light is very important. An office white
board may be helpful in accomplishing this.
Good Camera
You should get reasonable quality out of most cameras on the market today. Wirecast
has been tested with a low-end DV cameras to verify the quality of its Chroma Keying
system. However, the better the camera the better the keying.
If you use a cheap USB Web-cam, it may not give you enough source quality to get a
reasonable good key. But if you have excellent lighting, a USB camera works well. 3CCD
is better than 1CCD. If you have the choice, a PAL camera is better than NTSC, due to
how data is captured internally.
High Quality Video
If you are keying video from disk and not capturing it live, make sure the High Quality
Video option is checked in the Advanced Preferences Panel. This forces Wirecast to
decode the video from disk in the best quality possible, giving the Chroma Key the best