Still having trouble?
Let us use a simple 6-Camera Shoot (otherwise known as a Multi-Camera Shoot). Each one of those camera positions, feeds back to the truck to then be "mixed" or "switched" to create a visually appealing presentation for Broadcast, Streaming Applications, or DVD/Media Recording.... all in real time (or, Live).

... when we run a "Second" Vision Mix, we're essentially taking the same feed that the first Vision Mix/Switcher is receiving - and mixing/switching the camera inputs (or graphics) in an entirely different visual presentation. 

Here's a scenario, using the same 6-Camera Shoot.
The Client wants us (HD1 Live Mobile Television Production) to Stream a Live Multi-Camera shoot to their web-site while serving-up Pay-Per-View functions, as well as provide Audience Augmentation via High Definition Projector/Screen Combinations within the venue.

... for the sake of simplicity - the genre/type of event, is a comedy-tour.

Camera Positions 1 and 2, are instructed to always have a Tight-Shot, and a Medium-Shot - where Camera Positions 3 through 5 can be open for direction, audience reaction, and so on... with Camera Position Number 6, being a wide cover-shot (Perhaps one of our Jony-Jib's taking nice, wide, sweeping shots of the audience, stage, and talent).

The remaining Cameras/Inputs are monitored through three (3) Marshall V-MD434-3GSDI [a four (4) screen rack-mount] with two inputs remaining for convoy-module input.