Welcome the Filmmaker IQ.com
today we're going to explore the dolly zoom: an camera effect made famous by
Alfred Hitchcock in the film Vertigo
if you've watched film and television you've probably seen the dolly zoom
it's when a foreground element stays the same size with a background elements grow or shrink
It goes by all sorts of different names such as the reverse tracking shot
the zolly, the stretch shot, the forward zoom, reverse tracking, trombone shot
Contrazoom, telescoping or Vertigo Effect
in fact was Alfred Hitchcock who first implement this technique is 1958 film Vertigo
According to legend Alfred Hitchcock got this idea when he fainted at a party
and it was Paramount second unit cameraman Irmin Roberts
who developed with Hitchcock for the film Vertigo
since Vertigo the dolly zoom has been used and many other productions
including by Hitchcock himself in Marnie Steven Spielberg utilizes the effect in
Jaws in 1975
The sudden distortion a perspective isolates
zeroes in on Brody. His worst fears have become real
They should have closed the beach...
The Dolly Zoom was also used in Martin Scorsese's 1990 film: Goodfellas
In this conversation between Ray Liotta and Robert De Niro everything
seems normal on the surface
but the dollys zoom emphasizes that the world is slowly changing around them
He took the booth near the window so we could see everyone who drove up to the
restaurant
wanted to make sure I wasn't tailed
he was jumpy he hadn't touch a thing on the surface of course everything was
supposed to be fine
who were supposed to be discussing my case but I had the feeling Jimmy was
China sense whether I was gonna read amount to save my neck
Henry has just come to the realization that his best friend has just put a hit on him
and they're really are no good fellas in the life of crime
so why does the Dolly zoom work?
all boils down to the basics of photography were taking a
three-dimensional world
and reduce it to a two-dimensional image So let's imagine a camera obscura.
The most basic type of camera pinhole camera
we have a subject an aperture imaging plane
light rays from the subject travel through the aperture
in a straight line in onto the imaging plane now if we draw a straight line from
each edge the image plane back out through the aperture
we can construct in angle: this angle is our field of view
With a pinhole camera there's no way to increase or decrease our field of
view without moving the image plane
but we can use lenses with different focal length or zoom power
to bend the light as it enters the camera and now
we can see more what's around get a wider field of view
with a wide-angle lens or zoom in closer with a narrower field of view with a
telephoto lens
By bending the light though we introduce a phenomenon called
perspective distortion which is the warping objects based on the distance
from the camera
now perspective distortion doesn't change simply by increasing or
decreasing the focal length or zoom
if I sit here with the camera zoom all the way in I'm not going to notice a shifting of perspective
but it does change based on the relative position of the camera to the subject
compare these two shots left is a zoom in
while the right is a dolly in. The zoom in shot just magnifies the image
in the Dolly-in shot the surrounding objects are affected by the change in perspective distortion
caused by the camera movement and this is how the magic of the Dolly zoom works
we increase the focal length - we zoom in as we simultaneously dolly the camera out
or vice versa dolly in and zoom out
zoom keeps the frame crop the same so the foreground elements
stays roughly the same size throughout the move. This isolate the effect
of the perspective distortion caused by movement of the camera
and this shifting a perspective distortion is what creates the effect of the Dolly Zoom
Theoy is all well and good but it takes a little bit
effort to actually get decent dolly zoom in production: You're going to need two things
A Dolly and a Zoom: That should be pretty obvious: you can
try to do with a slider but you might run to the problem of having the slider get in
your shot and that's not good
I'd done it was a slider you just more limited as far as the zoom goes
you really need to have a camera with the smooth zoom
preferably a motorized servo controlled zoom it's nearly impossible to pull it off
with a photography lens
unless you're shooting stop-motion after all that's why it took until 1958
to achieve this effect the nearly smooth mechanical lens
in order to pull it off
Now to demonstrate I have a cut-out have maestro himself
Mr. Alfred Hitchcock: I'll start the shot dollied
all the way in and zoomed out I'll keep the aperature stop down so I get it deep
depth of field so I'm not fighting with the focus during this move
now as I move the dolly out I'll carefully zoom in at the same time trying
to match to speed of the zoom with the speed of the dolly
I want the opposite effect I'll dolly in for my final position
was zooming out either way I like to start with the Dolly all the way in because
i'm limited more by my wide angle I am by my telephoto
Getting this effect takes a lot of practice to get just right
as a speed which you need to dolly and zoom will change depending
on where you are in your focal length range: just keep doing a shot over and
over again until you get something you're happy with
Just realize it does take a little bit of time
there's history and science the craft of filmmaking
we're standing on the shoulders of giants the Dolly Zoom is a result
of Renaissance painters
scientists studying optics an uncredied second unit cameraman a legendary
director getting dizzy at a party
who with a talented cast and crew went on to create what many believe is the
greatest film ever made: Vertigo
Each step contributing to our collective understanding in our history
so go out there use it make something great
i'm John Hess and I'll see over there Filmmaker IQ.com