![Flip Flop](https://i1.wp.com/www.andydickinson.net/wp-content/uploads/2006/12/FlipFlop.jpg?resize=431%2C236 "Flip Flop")

Flip Flop is a nice little live preview app that may be of some use

FlipFlop is a small, free Mac OS X application designed to assist filmmakers with onset monitoring / previewing using a laptop and a firewire connected camera. The features came mostly from reading many peoples requests on various forums such as DVXUser and Redrock Micro