14.Main Video Source Selector: used to select which of the four video input channels or
background is sent to the Main video output.
15.Sub Video Source Selector: used to select which of the four video input channels or
background will be transitioned to or used as a sub source in an effect.
16.Chroma Key: when engaged, this removes the selected color from the Main Video Source and reveals the corresponding portions of the Sub Video Source. Repeated presses of the Color up and down buttons selects the color to be removed. Repeated
presses of the Level up and down buttons sets how much of the color will be removed. Color and level information are displayed in the windows above the Keypad (21.)
17.Preset selectors: control the 30 user programmable preset locations for storing
customized effects and transitions.
18.Picture in Picture: puts the selected Sub Video Source in a window on the Main Video Source, with control over window size and placement.
Used in conjunction with the Border keys (7.)
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