Screen shot of the portion of the computer screen showing the three windows and the selected angle.
Instead of having a static camera of a "talking head" I'm able to seamlessly switch from one camera angle to another in perfect sound and frame sync while I edit. In the past, if I wanted to switch between two cameras I would have to pull one clip onto the timeline in the editor and then find the second clip and try to find the exact exit point of the first clip and the exact entrance point of the second clip to make a (more or less) seamless change. Now I can switch back and forth with ease by just clicking the numbers 1,2, or 3 on my keyboard. You can watch all three camera angles live in their respective windows and you can also decide which clip's audio track is the best one to use by auditioning each one.
A few important things: If you can't "jam" time code on all three cameras (not possible with mine) it's vital to have decent audio tracks on all the clips you want to sync together. The programs (FCP X and Premiere) both use the audio waveforms to match the video clips to each other. You'll want to make sure you label each of your cameras to make housekeeping easier, and you'll want to add a name for each angle you will be using. Finally, you have to have all three cameras set to exactly the same frame rate for all this automated syncing to occur.
Having all three of our angles for each person's interview sync'd makes the editing process so much easier and more fluid. How did we ever live without this?
Once I get my hands on some good "B-roll" we'll have three sixty second video segments ready to go in no time.
Makes me wish we had a really long form video program to work on; that would make the switching so much more fun.
Finally, one of my video editing friends warned me: "Don't switch without a reason and don't do it so often that it becomes a habit. If you do you'll be making the equivalent of a excess zoom lens zooming that we all hated so much." Good advice. Use everything sparingly......
A good source to learn about multi-cam editing in FCP X? Why it's all right there in the Apple Support section of their website. Reading is mandatory.