Dolly zoom

Computer-generated representation of a dolly zoom
Frame from an animation showing a dolly zoom being performed. At the top of the image is the camera's view; the cubes stay the same size as the teapots in the background grow bigger. At the bottom of the image is a plan view showing the camera moving back while zooming in, illustrating how the effect is achieved.
In the video inset, the object moves with the camera and it does not zoom, so the FOV does not change; thus there is no dolly effect.

A dolly zoom (also known as a Hitchcock shot,[1][2][3] Vertigo shot,[4][2] Jaws effect,[4] or Zolly shot[5]) is an in-camera effect that appears to undermine normal visual perception.

The effect is achieved by zooming a zoom lens to adjust the angle of view (often referred to as field of view, or FOV) while the camera dollies (moves) toward or away from the subject in such a way as to keep the subject the same size in the frame throughout. The zoom shifts from a wide-angle view into a more tightly-packed angle. In its classic form, the camera angle is pulled away from a subject while the lens zooms in, or vice versa. The dolly zoom's switch in lenses can help audiences identify the visual difference between wide-angle lenses and telephoto lenses.[6] Thus, during the zoom, there is a continuous perspective distortion, the most directly noticeable feature being that the background appears to change size relative to the subject. Hence, the dolly zoom effect can be broken down into three main components: the moving direction of the camera, the dolly speed, and the camera lens' focal length.[6]

The visual appearance for the viewer is that either the background suddenly grows in size and detail and overwhelms the foreground, or the foreground becomes immense and dominates its previous setting, depending on which way the dolly zoom is executed. As the human visual system uses both size and perspective cues to judge the relative sizes of objects, seeing a perspective change without a size change is a highly unsettling effect, often with strong emotional impact.[citation needed]

  1. ^ Truffaut, François; Scott, Helen G. (1985). Hitchcock. New York: Simon & Schuster. p. 246. ISBN 9780671604295.
  2. ^ a b Norman Holland. "Hitchcock's Vertigo: One Viewer's Viewing". Archived from the original on 2015-01-01.
  3. ^ "The "Vertigo shot" and the oneiric frame". Archived from the original on 2007-09-15.
  4. ^ a b Cite error: The named reference S was invoked but never defined (see the help page).
  5. ^ Hardy, Rob (January 21, 2014). "Everything You Need to Know About the Dolly Zoom". nofilmschool.com. No Film School. Retrieved June 17, 2020.
  6. ^ a b Shields, Meg (2021-01-03). "How Does the Dolly Zoom Work?". Film School Rejects. Retrieved 2023-03-16.