In contemporary filmmaking, this camera trick is widely overused and rarely achieved correctly. Originally conceived by the master of suspense Alfred Hitchcock in his film Vertigo, it was 'stolen' by Steven Spielberg, becoming known as the Spielberg shot for its use in Jaws in the shot of Chief Brady on the beach when he spots an ominous black fin poking from the water close to swimming children. This was not so much a planned attempt by Spielberg to name a technique after himself, but more due to the success of Jaws and the timing of the effect in the film; everyone talked about it and the film, which gave birth to the term the Spielberg shot.

The mechanics

The combined use of a zoom, focus and track, timed perfectly, will produce this effect, or optical illusion. Individually, zooming and tracking are difficult enough manoeuvres on their own.

The zoom

A zoom is where the camera and subject stay still and a special lens zooms in to the subject from a distance, effectively closing the distance between the audience and the action without having to physically pick up the camera. The only problem with a zoom is it looks unnatural, as it relies on the optical capabilities of the camera and lens to produce the illusion of moving closer to a subject, effectively magnifying the subject. If you watch closely, you’ll see the background to the subject of a zoom will not alter perspective, and the relative positions and sizes of anything in the image will remain the same.

The track

Comparatively, a tracking shot is where the camera is moved closer to the subject through the use of a track and dolly. The track is simply just that; track, not unlike the rails a train runs on, but more lightweight and portable, in some cases collapsable¹, and can be made from metal or plastic. A dolly is the carriage that runs on such a track, but unlike a passenger train carriage this is a specially designed platform with coasters or wheels on each corner, and with a seat and mechanism designed to mount and secure a film camera and camera operator on top. There are many types and variations of track and dolly in contemporary filmmaking, but in Hitchcock’s days the tracks were usually metal and most mounts were suitable for one or two types of film camera.

The subject was generally situated at the far end of the track, and the director, or sometimes the director of photography, would sit on the dolly with a camera mounted on it while a number of crew, called grips would push the platform, or dolly along the track towards the subject. This had the effect of allowing the audience to move closer to the subject and the camera to make better use of lenses for effect. Unlike a zoom, the perspective of the background did change with a tracking shot, as the camera was physically moved closer to the subject.

The trombone

The trombone shot is, therefore, a combination of the two techniques above, coupled with the added difficulty of keeping focus.

With the camera mounted on a track and dolly, and the subject stood still, the camera begins to zoom in on the subject as it is pulled backwards on the track; all the while maintaining perfect focus on the subject. At a pre-determined spot the camera stops zooming, the grips stop tracking back and the focus puller stops rotating the focus ring. The difficulty is getting the speed of the backwards track and the speed of the zoom-in to match enough to create the effect, which is for the background to deepen in perspective (stretch, or drop away) while the subject remains the same size in frame.

The reverse of this, to track in and zoom out can be just as effective, drawing the background in and effectively closing the gap between the subject (a character or object) and its background.

Alternative names

There has never been one definitive name given to this effect, and although the 'trombone shot' has become something of an industry title, it has gone under many guises and names;

• Forward zoom
• Reverse tracking
• The 'Hitchcock' zoom
• The 'Vertigo effect'
• The 'Spielberg' shot
• Dolly Zoom
• Zoom-in, Dolly-out
• Contrazoom
• trombone shot

The name 'trombone shot' has its base in the physical motion of a trombone as it descends a sliding scale of notes or a glissando – the player pushes the slide outwards – and the descending tone it makes as a player does this and blows into a trombone. If you can imagine the sound and visualise the effect, there you have the basis for the name, 'trombone shot'. If you can’t, then go watch Vertigo.

Alfred Hitchcock used this technique in his film Vertigo to heighten James Stewart’s sensation of vertigo by making the drop from the building in the opening sequence seem all that more further - the illusion that the distance between the character and the ground increase or extends - and again, later in the film in the stairwell, to similar effect. Since then the effect resurfaced (no pun intended) in Steven Spielberg’s Jaws, after which the shot was done to death in countless films, TV shows and commercials.

An apparent quote by Hitchcock himself on the subject of the trombone shot;

'I thought about the problem for 15 years. By the time we got to Vertigo, we solved it by using the dolly and zoom simultaneously. I asked how much it would cost, and they told me it would cost fifty thousand dollars. When I asked why, they said Because to put the camera at the top of the stairs we have to have a big apparatus to lift it, counterweight it, and hold it up in space. I said There are no characters in the scene; it's simply a viewpoint. Why can't we make a miniature of the stairway and lay it on its side, then take our shot by pulling away from it? We can use a tracking shot and a zoom flat on the ground. So that's the way we did it, and it only cost us nineteen thousand dollars.'

Even with the advances of film technology the trombone shot is still a very physical one, demanding the use of a variety of grip and camera equipment, as well as a number of hands-on personnel. This means its successful production is very prone to human error, and unless prepared well in advance can prove a fruitless exercise. The advent of 3D environments has meant it can be reconstructed within the confines of a computer using software such as 3ds Max, Maya and Lightwave, and with Hollywood pumping out more and more 3D animations since Toy Story, be prepared to see it appear again very soon.

The DIY trombone

It sounds simple, and anyone with a camera and a skateboard or rolling office chair can attempt this shot. If you own these, why not try? (just be careful not to fall off your chair or skateboard, or whatever else you’re using as a DIY dolly, and always be aware of health and safety) Sit yourself on a high backed rolling office chair (eg one with coasters on its base or legs), take a video camera with a manual

²

zoom and focus demand

³

and focus on a subject (a person or object). Ask a friend or work colleague to then drag you backwards in your chair (slowly...) in a straight line while you attempt to keep the subject the same size in the viewfinder/on the screen as possible with the zoom control while keeping it in foucs by turning the focus control. It's best if you can record and watch back the results; while you’re focused on attempting the shot, you might well miss the effect.

It’s often a case of practise makes perfect with this shot, but the advantages of having a secure track and dolly, several members of crew and a good camera with good lenses becomes obvious the more you attempt it with simple DV cameras, skateboards and a best mate.