Christian,
So far, everyone has given you the best “professional” advice for a multicamera shoot. It’s good advice and well intended. It seems however, that you’re trying to do this with a “no budget” approach. Worse, the fine line between doing it or not doing it is the cost… right?
So, here’s a suggestion that is clearly NOT the best professional way to approach it… but will enable you to live switch a multicam shoot live to tape (or file) and then immediately review or distribute.
Check out this product called “Wirecast”.
https://www.varasoftware.com/products/wirecast/
It takes a firewire feed from a camera and allows you to live switch, add FX, titles, and best of all, go out directly to a webstream for live broadcast. It’s surprisingly cheap… only $450 bucks.
Look, there’s a right way to do this, and an “anyway” to do it. Three firewire cameras, a PC (or Mac) with multiple firewire ports and you’re in business, for pennies. Good luck.
Mark
PS, We use this program tied to a three camera setup to regularly create direct to the web programming. I can tell you that it works as promised, but in a “live” environment, may not be the easiest set up to deal with. However, weigh this against not doing it all due to cost.