A Contra-Zoom, also known as a Dolly Zoom, Vertigo Shot, or Zolly, is a camera technique in which the camera physically moves toward or away from the subject while simultaneously adjusting the zoom in the opposite direction. The result is a shot where the subject remains roughly the same size in the frame, but the background appears to compress or expand dramatically, creating a disorienting, unsettling visual effect.

The technique works by exploiting the relationship between focal length and perspective. As the camera dollies backward while zooming in, the subject stays framed consistently while the background appears to stretch and compress, flattening the sense of space. The opposite movement, dollying forward while zooming out, causes the background to expand and recede, creating a sense of the environment closing in. The effect was popularized in Alfred Hitchcock's Vertigo and has since become a visual shorthand for psychological disturbance, realization, or a sudden shift in perspective or understanding.

In AI video generation, the contra-zoom is a challenging effect to reproduce accurately because it requires precise coordination between camera movement and optical characteristics. While some advanced models can interpret this instruction when clearly described, it remains one of the more difficult cinematic techniques to generate reliably, and creators may need to experiment with prompt phrasing or consider post-production solutions for achieving this effect.