[Iain MacKinnon] “So let me get this, Camera 1 is pointing at my subject, output to a monitor, camera 2 is pointing at the monitor.
Is that right? then combine the 2 images in FCP?
“
Nope.
Cam 1: Subject
Cam 2: Monitor
ON the monitor is a LIVE combination (via a video switcher) of Cam 1 -AND- Cam 2.
BTW, the Cam 1 (subject) shot can be a video tape, but Cam 2 and the monitor must be “live.”