Dolly zoom effect definition
In this niche, there are many different techniques aimed at a specific effect, and dolly zoom is one of them.
Irmin Roberts was the one who invented the dolly zoom effect while working on Alfred Hitchcock’s "Vertigo". This technique had an impact on the audience, and since then, it is often used by directors to emphasize different feelings (anger, fear, falling in love, etc.) that suddenly evoke in the hero. For example, in "Jaws", Steven Spielberg showed the main character’s biggest fear through the dolly zoom effect. Since these two movies popularized the technique, it’s also often called the "Vertigo Effect" or "Jaws Effect".
The common name, however, refers to two different camera techniques – dolly and zoom.
Differences between dolly and zoom
"Zoom vs. dolly" can be a debate for an amateur video maker since both techniques can achieve similar results, but there are key differences.
When adjusting the zoom lens, you can visually change the distance to objects in the frame. However, all objects will be zoomed in or out simultaneously, regardless of their position relative to the camera.
On the contrary, camera movement is the main characteristic of the dolly technique – hence the name. The physical movement of the camera, most often by means of a dolly or slider, is natural to the eye since it reproduces approaching or moving away from the object, while the perspective of the background is changing at the same time.
With the necessary synchronicity, combining these two techniques allows you to achieve the following effect: the object in the center of the frame remains unchanged, and the surrounding space or background is deformed – which is a dolly zoom shot definition.
How to do a dolly zoom
Anyone can make a dolly zoom effect with a camera. And that is precisely why it requires cautious handling. It’s too easy to overuse it, therefore it should only be used when it’s 100% justified by the dramaturgy, expanding upon the character’s goals or personality, as well as the atmosphere of the scene, and also fits into the overall concept of the movie. Dolly zoom is most often used with several specific purposes and meanings, so find the one that suits you before starting shooting.
The dolly zoom technique consists in adjusting the lens to enlarge the object in the frame while simultaneously moving back from it (or vice versa, you’re zooming out and moving towards the object). When you concurrently apply these actions, only the depth of field changes and the object remains motionless relative to the viewer. You don’t even need to have a special camera cart, you can put a camera mounted on a tripod on a skateboard or shopping cart, and after a few training sessions, you’ll get a knack of it and it’ll be easier to repeat later. The main thing is not to forget to turn off autofocus, which in this case is completely redundant.
If you recorded a video using only camera movement or zooming with a lens, you can also create a fake dolly zoom effect during video editing. However, it works better for videos with a high resolution as some of it will be lost in the result.
To create the effect, you’ll have to find the parts where you want to apply it, then zoom in/out while keeping the horizon at roughly the same level. You can also adjust the position of the main object in the frame to make the effect more prominent. It won’t be the same as when you do a proper dolly zoom, but it still looks good, so try experimenting with that!