I've searched the forums, but can't seem to find anything, so time to make a post.
I am looking for a way to remotely trigger my camera (1D Mk II or a 50D) when a moving animal passes a specific point. Right now I use a pocket wizard setup, but that means I have to visually guess when the animal is crossing a point, hard to do when I'm tracking the action with a second camera. Is there something like an IR beam rig that triggers a camera when the beam is broken?
The remote will be about 50 yards from were I am standing with a wider angle lens, For this project it is working dogs on livestock, so no way I can get closer, nor is the location set up for me to be able to mark the crossing point to be sure I hit the pw at the right time. I will be shooting head on shots with another camera under my control. any help anyone can offer is appreciated.

