PAUL ON CALL: What is Keying?

Keying Defined… 

Luma keys (removes the black background) Provides a way to composite a foreground clip over a background clip based on the luma levels in the video.  This is most often useful for still images, such as a picture of a logo over a black background, or computer-generated graphics. 

Chroma key (removes the green background) A technique by which a block of a particular color (often blue or green) in a video image can be replaced either by another color or image, enabling, for example, a weather forecaster to appear against a background of a computer-generated weather map.

How can keying help me? 

Keying allows you to remove the lime green or black background from an image or video, and place / layer it over other live or recorded videos to create a composite.  This is great for putting texts/graphics on your broadcast or creating a virtual set. 

Software like OBS, VMix, or Wirecast gives you the ability to key your graphics for your broadcast. Most switchers will allow you to key using a switcher like the ATEM, Roland, or Ross switchers.