CamTwist + Blackmagic Intensity Thunderbolt Shuttle Settings
Solved the problem...

Go to: Mac System Preferences > Blackmagic Design

Set default video standard as HD 1080i 59.94 CamTwist > Blackmagic HD 1080i 59.94 - 8 Bit 

I figured out my camera settings using the Blackmagic Media Express app, which did detect the camera. Just take a look in the app's settings to find your camera's connection settings.