Sergiu Huzum's transtrav
 

The 'transtrav' device aparently was patented by a Romanian cinematographer, Sergiu Huzum and used it in one of his films in 1966. While I was in the film school, my optics lecturer, Toma Radulet - who probably was part of the engineering team - showed us a modified dolly with gears and cables linked to an Angenieux 25-250 zoom lens. It was dumped in a corner of the camera department store of the Buftea Film Studios.
As Mr. Huzum left the country to live in France, he became a 'persona non grata', considered a traitor by the communist governement. The device was sabotaged, some parts went missing in order to make sure nobody will use it again, at least for the memory and legacy of a very talented cinematographer.
I hope someone there will try to restore it.

Forced Perspective
 

I beleive the technique is called forced perspective. Dolly in, focus in and zoom out. The background will fade away and the subject will increase. Dolly out, focus out and zoom in, the background will appear to grow.

Forced perspective would generally refer to a set built to appear to be bigger than it is by faking the dimishing effect, like a street that gets gradually smaller in scale to appear to be disappearing into the distance. Example would be the corridor in "Willy Wonka" (both versions) that ends up at a tiny little door once they walk up it, or the exterior street set in "One From the Heart", plus many others.

There isn't an official industry name for the technique discussed here, I usually use "Vertigo effect" in honor of Hitchcock but I was also introduced to the rather delightful "zolly" meaning zoom/dolly, so I try to use that one.

that is precisely what it is. It is an illusion of forced perspective. be it a set or a camera move. it can be acheived easily if your are working at the end of your lens with a shallow depth of field.

Love the 'zolly' name. I think it will stick.

The best use of this shot IMO, is either Hitchcock's Vertigo or Scorsese Goodfellas, where Jimmy and Hnery are talking in the cafe towards the end.

fahrenheit 451
 

also check out the burning hallway shot in the school in:
Fahrenheit 451 Directed by
François Truffaut
the special features describe the shot and how it was done...

The end of panic room was a really slow reverse zollie...very cool.

I am going to need to employ this shot in my next short film, so I've been considering all options to get the best out of the technique.

My DoP tells me the best way of achieving this these days is using green screen. ie. Green screen your talent and composite him over the zoomed background.

An advantage to this, besides having not having to worry about zoom/track set up, is that you can select the best performance of your actor(s) without their best performance having to be scrapped on a poorly executed 'zolly'

Can anyone tell me any disadvantages to executing the shot this way (ie with green screen), as it's my first time doing the contra-zoom on set. Many thanks,

Kris

The negative aspect of doing the shot employing a green screen is that there'll be no change optically in your foreground subject over the course of the move.

Because of seeing the lens breath every other time you've seen that shot done, we've all come to expect a tiny bit of "zoom" and/or barrel distortion on your subject as the move happens. If you DON'T see that, it'll look very faked, IMO.

Unless you want to spend extra time posting that shot, i.e., manipulating the actor's compositing layer, you'd be better off doing it IC.

I'm kind of surprised your DP recommended doing it GS. Those shots are so fun to get right on set!

Jesse,

Big thanks on your feedback - much appreciated.

Yes, in the back of my mind, I figured there would be zero change to the foreground doing it green screen, which might make it look false, but not odd I thought.

Although, to be clear, I don't care much for the fun of trying to do it the traditional way or whether experts would point at it and say, 'that's not a true zolly!' ... All I care about is that it looks good and effective on screen. ie. Will the visual effect work the same way doing it green screen?

Another question, which looks better, zoom in / dolly back, or, zoom out / dolly in ?

My needs: Solo actor set up, sudden realization / horror, background object important to be seen / noticed.

Your choice depends if you want a sense of growing space or the background being drawn in.

Steven Spielberg was into them in this early days, apart from "Jaws" he used the effect in "Sugarland Express" drawing the approaching car onto the hidden marksman and his rifle in the foreground.

To me, the effect on the foreground is part of the total visual effect, so again, IMO, I don't think it'll be effective green screened.

But if you have any solid color wall to shoot in front of, you can do a quick and dirty test yourself to see if it's acceptable for you.

As for which method looks better, well, they look different. If you want the background to appear to stretch out behind your subject (providing a sense of being lost, alone, etc...) zoom out while dollying in. If you want to collapse the space between subject and background, zoom in, dolly out.

Dolly zoom - Wikipedia, the free encyclopedia