Oswald in the doorway: the blog of the Oswald Innocence Campaign, by Ralph Cinque

"There is absolutely no reason to look at the bottom trim of the limousine and pretend that's a straight line, and compare it to the bottom edge of the photograph, which is the bottom edge of the camera's view finder and thus not anything in the real world." Joseph Backes

No, Backes. We're saying that the base of the limo is a diagonal line. 

 Of course, the bottom line of the picture doesn't correspond to any object in the real world, but it does tell us something about how the camera was oriented. By the way, the Prof called your response, "cheap trolling."