Whether it's a gentle drizzle or a devastating deluge, rain has a fascination for all of us. We might pass a location several times a day, but when it's drenched in rain, it takes on a whole new atmosphere. As photographers, we enjoy seeing the commonplace in a new light (or dark), and with a camera along, we can capture this mood in pictures.
ISO 400 film, or ISO 200 with a digital camera, should be okay when you're taking pictures during a mild shower, but under cloudburst conditions the light level can drop to less than one-tenth the brightness of a sunny day. On these occasions you might need an ISO 1000 film or faster, or the highest digital ISO setting.
Remember that the faster the film, the grainier it is, and the higher the digital ISO, the more noise. But under adverse lighting conditions such as that found in a thunderstorm, added grain or noise is not objectionable. In fact, the additional texture can add to the effectiveness of a rain shot. Very seldom is fine detail a factor in this type of shooting, except, perchance, when you want to catch on film the expression of a hapless person soaked to the skin.
In a rainstorm, light reflected off raindrops can give an exposure meter the impression that things are brighter than they really are. To compensate, increase exposure somewhat. This can be done with the backlight button on a compact camera. On a camera with exposure compensating capabilities, increase exposure one or two stops with the aperture or shutter speed, or use the +1 or +2 exposure compensation option.
A wide-angle or normal lens (about 35-50mm) will reduce haziness in a rain scene and increase color saturation. This is not necessarily good. To enhance the impression of rain, you might want to use a telephoto lens to compress the density so colors will be more muted, and the haziness will be intensified.
If you have an adjustable camera and can mount it on a tripod when photographing rain, try to vary the shutter speed, going as low as 1/4 or 1/8 of a second, or the slowest shutter speed available. The slower the shutter speed, the more the raindrops will show up in pictures. With slow shutter speeds, raindrops will appear as streaks, but they probably will not appear at all with a shutter speed faster than 1/125. The more evident the raindrops, the stronger the impression that it's raining.
Besides a tripod, there are ways of steadying a camera for long exposures. If you're inside a building, you can press the camera against a window. Be careful, though, when squeezing the shutter release. Press it slowly so the camera doesn't move as the exposure is made.
When using a window for stability, you'll get the best results if it's single-pane glass. A double-pane window can cause undesirable reflections from the outside pane. Reflections can also be reduced, or even eliminated, if the lights are off in the room from which you are shooting.
If you can shoot from a window away from the direction of the wind, all the better. You might be able to open the window for brief periods of time to take pictures. If you can't open the window, go ahead and shoot anyway. Rain on the window can create some interesting diffusion effects. Everything in the scene will be fuzzy, but this can make it look even more realistic.
When photographing a thunderstorm from a car (the passenger side or rear seat, unless the car is stopped), the conditions are similar to those in a building. Shoot away from the wind and roll the window down if possible, or hold the camera tight against the window, except when shooting straight ahead. The front windshield slants, so try to include the dashboard, wipers and hood of the car to add more depth perspective to your pictures.
Rainy day photography can bring some interesting surprises. For example, a colorful umbrella or bright raincoat can provide excellent contrast, and possibly a much-needed focal point. Yes, rain can be a challenge, but isn't that what much of photography is all about?