What is a Dolly Zoom A dolly zoom is a technique used whilst shooting where the camera zooms in or out on a subject whilst the camera moves towards or away from the subject. When timed correctly , the effect created is that the subject should stay the same size whilst the background seems to compress or decompress. The most famous scene the dolly zoom was used in is from the film Jaws. The use of this technique can be to create a sense that the character is undergoing and extreme realisation.