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Zooming in filmmaking and television production is the technique of changing the focal length of a zoom lens (and hence the angle of view) during a shot – this technique is also called a zoom. The technique allows a change from close-up to wide shot (or vice versa) during a shot, giving a cinematographic degree of freedom.
Zooming can either be performed towards longer focal lengths, giving a "zoom in" effect: The filmed object will then increase in apparent size, and fewer objects become visible on film. Or it is performed towards shorter focal lengths, giving a "zoom out" effect: The filmed object will shrink in apparent size, and more objects come into view.
- Barry Casson. Zooming vs the Dolly Shot. YouTube.