Rainbows

If there's a silver lining for travelers enduring a rainy morning or afternoon, it's the potential for spotting one of nature's most charming phenomena, a rainbow. Elusive, ethereal, and always cheerful, rainbows can spark a feeling of mystery and romance in even the most jaded souls.

You may not be able to predict where a rainbow will occur, but you can increase your chance of seeing one by facing away from the sun toward the dark opposing sky after a storm. The best time to plan your rainbow shot is not after but during the storm. Use the rain time to scout around for potential compositions. Pictures of rainbows dangling in an open sky are pretty, but including an interesting foreground imparts a sense of scale and place.

Exposure is straightforward. Use your camera's exposure-compensation feature to underexpose by a half or a full stop for more saturated color bands. Also, polarizing filters reduce light by about 1 1/3 stops, so you might want to set a higher ISO speed to compensate for the lost light.

Here's a trick even some pros don't know about: Because rainbows are made of myriad tiny droplets of water that are reflecting light, you can use a polarizing filter to modulate the intensity of the colors. Simply mount the filter to the front of your SLR lens and, as you rotate it, watch in the viewfinder as the color bands brighten and then fade. Shoot when you see the saturation you want. Beware, though: In the wrong position, the filter will completely erase the colors. Also, polarizers reduce light by about 1 1/3 stops, so you may want to switch to a faster film or mount your camera on a tripod.