To achieve the effect the camera needs to be positioned at a certain distance from the object that is supposed to remain still during the dolly zoom. The distance depends on how wide the scene is to be filmed, and on the field of view (FOV) of the camera lens. Before calculating the distances needed at the different fields of view, the constant width of the scene has to be calculated. For example, a FOV of 90° and a distance of two meters yield a constant width of four meters, allowing a four-meter-wide object to remain still inside the frame during the effect.
Famous quotes containing the words distances and/or calculating:
“I was surprised by Joes asking me how far it was to the Moosehorn. He was pretty well acquainted with this stream, but he had noticed that I was curious about distances, and had several maps. He and Indians generally, with whom I have talked, are not able to describe dimensions or distances in our measures with any accuracy. He could tell, perhaps, at what time we should arrive, but not how far it was.”
—Henry David Thoreau (18171862)
“I know that the right kind of leader for the Labour Party is a kind of desiccated calculating machine.”
—Aneurin Bevan (18971960)