Field of View (FOV) for the stand-alone iSight?

I am developing a vision system for the Search and Rescue Robot team from Ohio University. I have been trying to find the field of view (FOV) for the iSight. On the box, it lists it as 54.3 degrees, but I don't know whether this is verticle, horizontal, or diagonal. So, if any of you know, I need the following:

horizontal and verticle FOV
or
diagonal FOV