How do you achieve the following camera technique

[Kevin Kwak]

Hello,

I wanted to learn this one camera technique that I see very often, whether it be in a music video, television show, and in a movie. The camera focuses on one character, the camera zooms in into the character 'while' the background appears to be zooming out.

The actor zooms in and the background zooms out simultaneously.


How would you achieve this camera technique? Thank you in advance.

[Giroud Francois]

this is a transtrav, technique employed by Mr Hitchckock.
if you are doing cinema, no other way than having the cameraman zooming manually while moving the camera backward.
this is pretty hard because you need to keep the subject at same size (if possible), compensating the movement of the camera with the zoom and in the same time you need to keep focus too.
With video you can cheat with blue/green screen technology.

[Shaun Williams]

Other names for this technique are contra-zooming, trombone zoom and dolly zoom. It basically relies on the characteristic differences between short snd long focal lengths.

A short focal length (i.e. a wide angle) will give you much more apparent distance between objects in the foreground and objects in the background. Conversly, a long focal length will appear to flatten an image, giving you the illusion that there is little distance between foreground and background.

In order to keep the foreground object the same size while zooming, you must alter the foreground object's distance to lens relative to the focal length you are changing to - this keeps the foreground object the same size in frame.

So, in order to have the background appear to move backwards, you need to zoom out to a shorter focal length, while tracking (trucking for you US citizens I believe) towards your foreground object. The opposite is true should you wish the background to appear to move towards your foreground object.

To achieve this you should also watch out for a couple of things. Firstly you would normally have a focus puller, especially when zooming in, as this reduces your depth of field. Zooming out isn't quite as critical as wider lenses will give you greater depth of field. Of course if your camera operator is moving the camera and also zooming, he or she doesn't have enough hands to rack the focus so you'll need another pair of hands.

Also, focal length changes are often accompanied by the need to change the apperture size on many lenses, thus you should keep a close eye on exposure.

Hope that helps.

Shaun

[Rob Lohman]

Also do keep in mind the effect has become a bit of a cliche over
time, due to over-use... So when this is the case and it is very
hard to execute perhaps it is better to think creatively and come
up with some other nice visual way to create the feel in a different
way etc.?

[Darko Flajpan]

You're right Rob, this is very hard to do effect, I've done it four times in my 12 yrs of my carrier, but when done properly it's really nice to see. From my expirience hardest thing is to mantain correct focus. Since i was doing that with broadcast cam and lenses, i am wondering how would thing work with AF?

[Kevin Kwak]

I appreciate your responses Giroud, Shuan, Rob, and Darko. I can't wait to attempt the transtrav, contra-zooming, trombone zoom, dolly zoom, or whatchamacallit. :)

[Charles Papert]

My favorite term for it is "zolly" (zoom/dolly).

I have found the hardest aspect not to be focus (yes, you need a focus puller, and it's no different than a regular push in/out) but coordinating the zooming with the physical motion. Zooms are non-linear, meaning that as you get towards the wider end, it requires less rotation of the barrel to maintain the same rate of widening of the angle of view. Thus you have to feather off the speed of the zoom as you move towards that end (or vice-versa), which has to coincide with the inevitable feather that is required as the dolly decelerates to a stop. There is a device out there that involves a decoder on the wheels of the dolly and will automatically adjust the zoom accordingly, believe it or not...! Too expensive for most folks though.

I recall one night a few years ago having to do this effect as we pushed in on four individuals, shot one at a time. It took hours to get them all right, and it more than tested our patience.

I was thinking about this effect this week as we were shooting at the Biltmore Hotel in downtown Los Angeles, fantastic location that, I learned, housed the wrought iron staircase used by Hitch for this effect in "Vertigo". Nifty.

[Rob Lohman]

I did a search on that hotel, it looks incredible from the photos I
saw. I don't even want to know the rate to stay there, heh.

[Jesse Bekas]

<<<-- Originally posted by Darko Flajpan : You're right Rob, this is very hard to do effect, I've done it four times in my 12 yrs of my carrier, but when done properly it's really nice to see. From my expirience hardest thing is to mantain correct focus. Since i was doing that with broadcast cam and lenses, i am wondering how would thing work with AF? -->>>

I had to do one of these "zollies" on a short last month using a non-tracked Dolly (a nightmare to keep straight) and a DVX100A. In mid-move the lighting changed dramatically, but I tried it with AF and it worked like a charm. No hunting whatsoever.

[Jacob Ehrichs]

Yeah, this topic is a little old, but I thought I'd bump it, rather than start a new thread. My question is if this effect is possible with the XL1? I've attempted to zoom and focus at the same time on the lens and only one of the functions will work. I probably need to switch to the full manual lense to get this effect. Guess I have to break out the 14x lens.

[Phil Hamilton]

Zolly? I like that term. The first time I ever really noticed a zolly was in JAWS. When Cheif Brody is on the beach staring at the water and the people start screaming - Speilberg zollies him - great effect.

[Peter Jefferson]

i do this with weddings (candles on altars and Wedding cakes... in fact) its not that hard to do with AF, a steady hand and a decent zoom rocker...

oh and 3 years practice on the bloody camera...

[Andy Graham]

the best example of the contra zoom is in goodfellas when ray liotta and rob deniro are sitting at the table in a diner and the background comes in so slowly you hardly notice it.No change in the size of the characters...welll executed

Andy.

[Nick McCarthy]

The term I've always heard is either calling it a compression shot (Or expansion, depending on which way you're going)

It's a great effect, but really requires the use of a nice dolly.

http://en.wikipedia.org/wiki/Vertigo_shot

[Emre Safak]

There is another great example in The Lord of the Rings where the camera zollies on the hobbit while the leaves rustle.