Focus on Travel Photography
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In addition to offering you the marvelous convenience of being able to change focal lengths quickly between pictures, zoom lenses enable you to create a novel special effect by changing focal lengths during an exposure. The result of this zoom effect is a relatively sharp central subject engulfed in a radiant burst of light streaks. The effect works best with a strong color or tonal contrast or with a brightly colored subject set against a dark background.
With your ISO set to a relatively slow speed (ISO 100 or 200), take a meter reading of your subject with your camera's exposure mode set to either shutter-priority or manual mode. The effect is most pronounced when you zoom through the entire focal range, so choose a relatively slow shutter speed—preferably 1/8 second or longer. To make the exposure, simply press the shutter button with one hand and slide or twist the zoom through its focal range with the other. Coordinating your two hands on the two controls takes some practice, but the slower the shutter speed, the more time you have to unravel the logistics.
Using a tripod is essential, because you're going to need both hands to operate camera controls and because once you begin the exposure, the reflex mirror of your DSLR will be locked up, blocking your view of the subject. It's also simpler to compose the picture if you zoom from the longest focal-length setting (telephoto) to the widest (wide-angle); that way you know for sure what will be in the center of your frame.
Once you are comfortable working with stationary objects in broad daylight, try something a little more challenging, like a sports-action shot. The added dynamics of the zoom streaks intensify the impression of speed and motion. Night shots are also powerful—as you zoom, each little droplet of light becomes a scintillating trail of color.