I edit lots of weddings for some company and I've noticed that most of the footage I get doesn't completely fill my preview window. There is a thin strip of black on the sides as if the video was slightly cropped, but it's not. The black is only at the very edge and is well outside of the safe areas, but you can see the black when you make a transition such as a 3D spin. At first I though that maybe it was the brand of mini dv tapes that their shooters were using but when I shoot with their brand of tape, my footage fills the entire window. I have a canon GL2. Their shooters use mostly sony dv and a canon xl1s. Is this because their cameras do not produce as big an image as the vegas window? I've noticed that when producing a 720x480 image in photoshop, the image is slightly smaller than the video window in vegas. So that made me think that maybe vegas has a slightly oversized preview window and most dv cameras (with exception to the GL2) produce a standard 720x480 image that is slightly smaller than the vegas window. Can anyone fill me in on what is actually taking place here?

Thanks
-Jim