How do they achieve this movie effect?

I was watching Behind Enemy Lines last night, and I noticed a cinematographic (is that even a word?) effect that was really neat. It’s an effect I’ve seen before, but I’ve always wondered how to do it. Basically:

It looks almost like a zoom-in. The background zooms in, so you focus in on a smaller part of it. However, the relative size of the subject of the shot does not change. It’s often used to give the appearance of sudden realization on the subject’s part (in this case, that he stepped on a mine). To express it in a graphical manner:

The viewing field of the camera goes from something like this:

\             /
 \           /
  \    S    /

To something like this:

   |         |
   |         |
   |    S    |

Where S is the subject of the shot. Note how the relative size of S would remain the same, while the amount of background seen reduces.

So how do they do that?

It’s usually referred to by DPs and directors as a “smash zoom.” It’s achieved by using a telephoto lens on the camera and simultaneously pushing the camera itself in on a dolly, while zooming out with the lens. So while the foreground figure retains its size and focus in the frame, the background moves in and the depth of field flattens.

Probably the two most famous uses of the smash zoom are the POV shots for Jimmy Stewart’s character in Vertigo and the closeup of Roy Scheider sitting on the beach seeing the boy get killed in Jaws. There’s also a great moment in E.T. where Spielberg uses it twice in a single camera setup.

They start off the shot with a camera relatively far away, equipped with a telephoto lens. Then they roll the camera towards the subject, while at the same time backing off of the zoom on the lens. This keeps the character looking the same, but gives the background that effect you noticed.

You can do the same thing with your camcorder at home. Just takes a little practice to de-zoom (?) at the same rate you approach the subject.


But mine had a new word in it. De-zoom.

That effect is called a “dolly zoom” and is done by simultaneously zooming in on the subject while dollying out, or vice-versa. I think it was first used by Hitchcock in Vertigo. I’m sure an expert will check in shortly with a better explanation

Yeah, actually, I sort of thought that would be what it was, but when I was visualizing it all in my head, it never quite fit together right. As an additional question: what happens if you do the reverse? Pull out while zooming in?

Also, I once again marvel at the efficacy of turning to the SDMB for answers to my pointless questions :slight_smile:

I was tardy clicking the “Submit” button :slight_smile: That’s my excuse

The method was also recently used, IIRC, during the fade-out shot of Panic Room, as Jodie Foster & daughter sit on a park bench.

In the documentary about cinematographers Visions of Light, Michael Ballhaus discusses his use of this kind of shot in GoodFellas, although it’s an extremely slow version of the shot (couple of minutes) so you only really notice it if you’re paying attention to the background and not the foreground where the action is (it’s where Ray Liotta and Robert DeNiro are talking in the diner).

Personally, I don’t like the effect. Although it does give the impression that the subject suddenly becoming more aware of his or her surroundings, it’s too distracting.

Suddenly I’m not paying attention to the story, I’m thinking about cameras and zoom lenses.

Manduck, you did just fine. It IS an annoying effect when done too fast, and yet it has been used a lot. The Goodfellas shot works very nicely but as was pointed out, it was done very slowly.

Ballhaus loves Arriflex, the odds are that it was pre-calculated and programmed into the zoom motor of his FI+Z control, and in fact once begun, it proceeded and finished without human interference.

Cartooniverse, whose IATSE card says, " D.P." on it

Cartooniverse, you just set yourself up for a bunch more questions:



FI+Z control? (something about zoom?)


This technique (synchronise the movement of the camera + the adjustment to the telephoto lens) can produce either an apparent decrease in depth of field (everything becomes flatter) or an apparent increase in depth of field (everything becomes deeper). It has been used both ways in movies.

See my last post

Try this

Right here

FI+Z control? (something about zoom?) [/quote[
3 out of 4 ain’t bad. :slight_smile:

Zoom in Dolly Out. Alfred Hitchcock was doing it 50 years ago, but I guess it’s easier to use a computer these days.

^5 ArchiveGuy. I was posting very similar stuff,when I had to flee rather quickly due to family emergency last night. The FI+Z system is just that, Focus Iris plus Zoom. Most high-end film cameras use them, they’re an outboard- and sometimes wireless-interface box for the onboard computer that allows shutter angle shift, frame rate shift on the fly, etc. Nifty tool

AKAIC, “Visions of Light” is one of the bibles in our business. The film of it isn’t bad either.

Tapioca Dextrin, it wasn’t meant as a slam to mention the use of the computer. It still requires the steady hand of a Dolly Grip. ( I’m fairly sure that the Goodfellas shot wasn’t done with a motion controlled dolly…) Hitch gets the kudos for coming up with many pieces of film vocabulary, this is but one of them.

I had a lot of fun with this on a short, local train ride. The train’s speed and the rate at which my camcorder zoomed in and out worked out perfectly.

…how’d you get the train to back up that fast?..