These intentional overexposures are a great way to break the rules and give your shots-especially portraits-a high-fashion kick. Ultimately, it doesn't matter what you know about lighting to create high-key photos. You can do it all with exposure, creating a high-energy, high-style photograph.
Not every image can, or should, be high key. To create a high-key shot without augmenting natural lighting, start by taking a good look at the subject and background. The foundation of a great high-key image is a preponderance of tones in the white to light-gray range, with few dark areas making their way into the finished image. That means a portrait subject, for example, shouldn't be dressed in dark clothes, and a background shouldn't be shadowed and moody. For a light, bright and airy shot, choose a subject already leaning toward those qualities.
Choose a portrait subject, for example, with fair skin and light hair. Dress them in light-colored clothing and find a softly illuminated spot in which to photograph them. You can even do it outside in shade with a bright-sky or sunlit background behind. This way exposing correctly for the subject will create a minimum of dark areas in the shot, and the soft, even light will minimize dark shadows and make a more flattering portrait.
But we're not just after a "not dark" image; we want high key. True high-key images impart a particular mood, and the key comes from the subtle overexposure. In the days of film, transparencies were perfect for high-key shots because of their minimal latitude. Shooting digitally, consider overexposing by a half stop to as much as two stops. If you're shooting RAW, don't hesitate to make the bulk of the overexposure adjustment after the shot is downloaded to the computer.
Whether the adjustments are done in camera or in the computer, the key is the preparation: With the proper subject, background and positioning, a big-time overexposure can still make the perfect shot-a high-key portrait with pristine skin and a light, bright, natural feel.