Crossing the line and library footage

Crossing the line: hopefully this will look OK with the fonts the web site uses... I think they're fixed width so the diagrams should line up.

Basically, unless you're deliberately trying to disorientate the audience, you need to try to keep objects in the same relation onscreen when you cut between shots. For example, suppose you have two people talking, A and B, seen from above:

x
/ \

A<-line->B

\ /
y

Suppose you shoot from camera position x; you'll see something like:

----------
| |
| B A |
| |
----------

Now regardless of where you position the camera on that side of the line between A and B you'll get the same relationship; A will be on the right of the screen and B on the left.
But if you now cut to camera position y, you'll get:

----------
| |
| A B |
| |
----------

So A and B will suddenly jump to the other sides of the screen, which is generally distracting.

That's really all there is to it. You can often get away with crossing the line (a friend's film I edited did it so many times that I told him he should retitle it 'Crossing the line', as that was both a good description of the plot and the edit!), and sometimes you want to do it, but to begin with you should avoid it wherever possible.

Phil

If you are filming a moving object (person, car, whatever) then you can imagine a line drawn along the path that the object is travelling. As long as your viewpoint (camera position) remains on one side of that line, the object will always appear on the screen to be travelling left-to-right or right-to-left, depending on which side of the line the viewpoint is on. I believe 'crossing the line' refers to when you cross that imaginary line and the moving object suddenly appears to the audience to have changed direction, and will be going back to where it came from. If you need to cross the line, then a common suggestion is to include a shot looking towards the front of the object as a link.

I've no idea where to get cheap clips - have you done some browsing?

Regards

Nigel

(PS Unicorn's reply which I've just seen is of course very similar - except instead of direction changes people will appear to jump from one side of the screen to the other)

[This message has been edited by Nigel Longman (edited 03 August 1999).]

Of course it gets more complicated when you have dialog while people are moving; one of the most common examples of crossing the line on TV and in movies is a conversation between driver and passenger in a car.

In this case you have two lines: the line between the two characters, and the line of motion of the car... and the two lines are (normally!) at right-angles to each other. One option is to shoot from the bonnet looking back through the windscreen into the car so that you don't have to worry about motion, the other is to shoot through the side windows; the background motion will switch in each shot, but you're still maintaining the line between the characters, which is more important. I can't think of any good examples offhand, but I've seen plenty.

Basically whenever you're shooting you need to keep track of where the important lines are, and which is the most important at any time. After a while it just comes naturally... with the possible exception of three-way conversations, which can be hell.

Thanks folks,

That certainly clears the line crossing
thing.

Nigel, I have done some browsing a while
ago and I found a US site that had free
footage but it was only available to US
citizens. I've since lost that link after
changing machines! I was wondering if there
was a UK equivalent?

Phil