DV (and SDI) both produce a lovely 4:3 picture on your tv screen and on the FCP canvas. If you have a perfect display, you should be able to take a ruler and grease pencil and measure it.
However, because of the oddball shape of the pixels making up the image, the actual, real
pixel count is 3:2.
3/2 = 1.5
720/480 =1.5
I don't know why Final Cut included 3:2 in the capture specifications. I've never seen the numbers written that way anywhere else. Tooooo much information.
Koz