I'm trying to find out what cables my crew will need to send an SD signal from the camera (Sony EX1 xdcam) to a BNC connection which will run a video on a large jumbo-tron type screen. At the same time we will need to be recording in 1080i 30fps.
You have a choice between Component or Composite or SDI. You'll need an RCA to BNC adaptors for either Component or Composite connections. You also have the choice of sending out a 16:9 image or a cropped 4:3. Are you renting the camera? If so, make sure they give you the cable that connects to the mini jack on the camera.
Forget composite out. It's horrible. Component out will require three connectors, but it will give you close to 800 lines of rez. There are some specialty cables out there for the EX1. It comes with a mini usb to RCA component cable.