Color matrix is a form of picture profile in the camera, the color matrix defines the way Red, Green and Blue signals from the sensors are combined. But this results in drastic change in color tint of the cyclorama area which may generate undesirable keying results. To get the best keying output, the color matrix node is introduced to create a post keying color matrix which can be matched with the original camera matrix profiles. The end result is you achieve the best keying while preserving the desired camera matrix profile.
Color matrix such as BBC, EBU, 1:1 are some examples. Color matrix 1:1 is neutral and does not affect the basic color matrix that the camera generates. Since the nature of Reality virtual studio production is sensitively based on how the cyclorama color is captured by the camera and sent to Reality Engine for keying process, any color matrix applied (except 1:1) in the camera may result in non appropriate cyclorama (commonly green) color which may affect keying quality.
To cater to this problem, introducing the COLOR MATRIX node which has the properties to set RGB color matrix.
Let's see below, how to use color matrix on node graph and achieve the desired color matrix of the camera.
First set the broadcast camera to desired color matrix (other than 1:1), you will notice change in the color balance.
Place some colorful object which includes red, green and blue shares and compose the broadcast camera to fit these objects.
Add a STILL STORE node and take a still store of the camera output, see below: