Controlling the Zoom

In addition to letting you choose an appropriate focal length when you frame a shot, zoom lenses allow you to change focal length during a shot, using either a mechanical control button or by manually turning the zoom ring on the lens itself. Unless you’re trying for that “caught-on-tape” look, a good zoom needs to start out slowly, ramp up to the desired speed, and then gradually slow to a halt. You can also conceal a zoom by combining it with a pan or tilt.

The mechanical zooms found on most low-end consumer video cameras can be difficult to control—they tend to start awkwardly, go too fast, and respond jerkily to any fluctuations in pressure on the button. And unfortunately, many low-end video cameras have lenses that do not have a manual zoom ring. In either case, practice makes perfect—give your camera operator (or yourself ) time with the camera before the shoot to get a feel for how the camera’s zoom works.

A word to the wise—if your camera doesn’t let you make a smooth zoom, then zoom as quickly as possible. A snap zoom has two advantages: it hides shakiness, and it takes up a minimal amount of time, making it easier to cut around later when editing. Higher-end cameras have zoom lenses that have a handle that lets you change the focal length really fast for better snap zooms (refer to Figure 7.2).

Many consumer-grade video cameras also have digital zooms, which are accessed through a menu display. Digital zooms are best avoided, since they work by blowing up the image rather than moving the optics of the lens, resulting in a low-resolution, pixelated image.

Figure 7.8

These four images were shot using four different focal length lenses: very wide, wide, normal, and telephoto. The camera’s position was adjusted to keep the framing similar. Notice what happens to the tree in the background.