Neither is ideal—correct exposure is best—but if you have to miss slightly, avoid blowing important highlights. Once highlights are clipped, that detail is gone and cannot be recovered. Slight underexposure is usually more recoverable from RAW, though lifting shadows can increase noise and reduce tonal smoothness.

A good practical approach is to expose as bright as possible without clipping important highlights (“expose to the right” / ETTR). Use your histogram and highlight warnings to check exposure. In harsh midday sun, very bright highlights and deep shadows can exceed the camera’s dynamic range, so even a perfect exposure may involve compromise.

For more natural-looking portraits outdoors, reduce scene contrast when possible: move to softer light, change angle, shoot at a better time of day, or use a reflector or fill flash. If contrast is extreme, exposure bracketing can also help.