Film technique question at DVinfo.net

Marc Colemont · February 12th, 2006, 08:54 AM

In a scary move you see sometimes a film effect were the hallway becomes longer like infinite while the actor is standing still. How do they do that?
Is that done with green screen, while changing the background?

Mike Marriage · February 12th, 2006, 09:26 AM

Can you give an example so we know what you mean? Do you mean a trombone shot (well it has a million different names)? This is seen in Jaws, when Roy Scheider sees the shark attack the young boy, on Fellowship of the Rings when Frodo senses the Dark Rider approaching and they hide under the tree. It was made famous by Hitchcock in Vertigo to demonstrate an uneasy feeling when James Stewart looks down the stairs. Apparently the effect was invented for that film by one of the camera department.

It is achieved by changing zoom on the lens and dollying the camera at the same time so that the subject stays the same size in the frame. This creates an effect of the background "warping" whilst the subject does not.

Emre Safak · February 12th, 2006, 10:27 AM

It's also called a "zolly".

Mike Marriage · February 12th, 2006, 12:39 PM

Quote:

Originally Posted by Emre Safak

It's also called a "zolly".

I've never heard that one. Everyone seems to have a different name for it. I've heard one or two people call it a conta-zoom as well.

Andy Graham · February 12th, 2006, 12:48 PM

This was also discussed in the thread below.

http://www.dvinfo.net/conf/showthread.php?t=42725

Andy.

Charles Papert · February 12th, 2006, 01:19 PM

Hey cool, the "zolly" name is indeed appearing to stick. Perhaps I should have somehow appended my name to it, assured my legacy etc...!

Marc Colemont · February 12th, 2006, 03:19 PM

I knew this forum would give me the answer the same day. Great.
I always wondered how do did it. Last night I saw a movie were they used it. It was done perfectly and at the right moment. Which made the moment overwhelming. Now that I know how they do it, I realize how difficult it must be to do it manually with the zoom. Mr Hitcock, my hat off for inventing this.
(My wife sometimes asks me if I'm watching the story of the movie, or watch only how they produced and made it... at least I will not be wondering around the house anymore how they did this one)

Mike Marriage · February 12th, 2006, 05:03 PM

Quote:

Originally Posted by Marc Colemont

...Mr Hitcock, my hat off for inventing this...

According to imdb, it was actually the second unit cameraman Irmin Roberts:

http://www.imdb.com/title/tt0052357/trivia

Charles Papert · February 12th, 2006, 05:23 PM

Yeah, I've done it a number of times and it never gets easier. The trick that the person who operates the zoom lever has to understand is that generally there is an exponential nature to the mechanism which is that the same amount of lens rotation will have a greater and greater effect as you go wider, which requires one to ramp down the speed of the zoom as you get to the end. It's especially hard if you need to keep the beginning or end (or --shudder--both) of the move intact for the scene, as that requires the dolly grip and the assistant or operator (whoever is zooming) to feather their start and stops together.

The Scorpio remote lens control system has a way to automate this by attaching an encoder to the dolly wheel and then regulating the focal length automatically to maintain image size once calibrated--never seen it used though.

With a remote zoom control on the gimbal of my Steadicam I've managed to hack my way through an approximation of the effect, but you really want the accuracy of the dolly to do it right.

Jason J. Gullickson · February 13th, 2006, 10:53 AM

What's the difference between this and a "trombone" shot?

Mike Marriage · February 13th, 2006, 11:31 AM

Quote:

Originally Posted by Jason J. Gullickson

What's the difference between this and a "trombone" shot?

Nothing, they are just different names for the same thing.

Marc Colemont · February 13th, 2006, 03:25 PM

It's all very interesting stuff. I tried it, and it's damn difficult to do.
Is there a trick to learn it the best way? I bet the actor is the one with the best patience in all this...take 113.

February 12th, 2006, 08:54 AM	#1
Marc Colemont Major Player Join Date: Nov 2005 Location: Belgium Posts: 695	Film technique question In a scary move you see sometimes a film effect were the hallway becomes longer like infinite while the actor is standing still. How do they do that? Is that done with green screen, while changing the background?

February 12th, 2006, 12:48 PM	#5
Andy Graham Major Player Join Date: Dec 2005 Location: Lanark,Scotland Posts: 736	This was also discussed in the thread below. http://www.dvinfo.net/conf/showthread.php?t=42725 Andy. __________________ Actor: "where would that light be coming from?" DP: "same place as the music" -Andrew Lesnie-

February 12th, 2006, 01:19 PM	#6
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	Hey cool, the "zolly" name is indeed appearing to stick. Perhaps I should have somehow appended my name to it, assured my legacy etc...! __________________ Charles Papert www.charlespapert.com

February 12th, 2006, 03:19 PM	#7
Marc Colemont Major Player Join Date: Nov 2005 Location: Belgium Posts: 695	Thanks. I knew this forum would give me the answer the same day. Great. I always wondered how do did it. Last night I saw a movie were they used it. It was done perfectly and at the right moment. Which made the moment overwhelming. Now that I know how they do it, I realize how difficult it must be to do it manually with the zoom. Mr Hitcock, my hat off for inventing this. (My wife sometimes asks me if I'm watching the story of the movie, or watch only how they produced and made it... at least I will not be wondering around the house anymore how they did this one)

February 12th, 2006, 05:23 PM	#9
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	Yeah, I've done it a number of times and it never gets easier. The trick that the person who operates the zoom lever has to understand is that generally there is an exponential nature to the mechanism which is that the same amount of lens rotation will have a greater and greater effect as you go wider, which requires one to ramp down the speed of the zoom as you get to the end. It's especially hard if you need to keep the beginning or end (or --shudder--both) of the move intact for the scene, as that requires the dolly grip and the assistant or operator (whoever is zooming) to feather their start and stops together. The Scorpio remote lens control system has a way to automate this by attaching an encoder to the dolly wheel and then regulating the focal length automatically to maintain image size once calibrated--never seen it used though. With a remote zoom control on the gimbal of my Steadicam I've managed to hack my way through an approximation of the effect, but you really want the accuracy of the dolly to do it right. __________________ Charles Papert www.charlespapert.com

February 12th, 2006, 09:26 AM	#2
Mike Marriage Major Player Join Date: Sep 2005 Location: NE of London, England Posts: 788	Can you give an example so we know what you mean? Do you mean a trombone shot (well it has a million different names)? This is seen in Jaws, when Roy Scheider sees the shark attack the young boy, on Fellowship of the Rings when Frodo senses the Dark Rider approaching and they hide under the tree. It was made famous by Hitchcock in Vertigo to demonstrate an uneasy feeling when James Stewart looks down the stairs. Apparently the effect was invented for that film by one of the camera department. It is achieved by changing zoom on the lens and dollying the camera at the same time so that the subject stays the same size in the frame. This creates an effect of the background "warping" whilst the subject does not.

February 12th, 2006, 10:27 AM	#3
Emre Safak Trustee Join Date: Feb 2004 Location: Brookline, MA Posts: 1,447	It's also called a "zolly".

February 13th, 2006, 10:53 AM	#10
Jason J. Gullickson Regular Crew Join Date: May 2005 Location: Madison, WI Posts: 170	What's the difference between this and a "trombone" shot? __________________ Jason J. Gullickson Producer the second society http://2soc.net

February 13th, 2006, 03:25 PM	#12
Marc Colemont Major Player Join Date: Nov 2005 Location: Belgium Posts: 695	It's all very interesting stuff. I tried it, and it's damn difficult to do. Is there a trick to learn it the best way? I bet the actor is the one with the best patience in all this...take 113.