When a person's face is much darker than a very bright background, what specific light measuring method helps you expose their face correctly?

When a person's face is much darker than a very bright background, the specific light measuring method that helps expose their face correctly is spot metering. Standard camera light meters are designed to calculate exposure based on the assumption that the scene, or the area being measured, averages out to an 18% gray reflectance value, which is a mid-tone. If you use a general metering mode, such as evaluative or center-weighted, the meter will be heavily influenced by the overwhelmingly bright background. This will cause the camera to underexpose the entire image, making the person's face appear even darker, or a silhouette, because the camera tries to make the bright background a neutral mid-tone. Spot metering specifically isolates a very small area of the scene, typically between 1% and 5% of the frame, and measures only the light reflecting from that precise spot. To correctly expose the face, you would aim the camera's spot meter directly at the person's face. By doing this, the camera's light meter ignores the bright background entirely and calculates an exposure setting that will render the measured area—the person's face—as the desired 18% gray mid-tone. This ensures that the face is properly exposed and visible, even if the bright background becomes overexposed as a result. For example, if a person is standing in front of a brightly lit window, pointing the spot meter at their face will tell the camera to adjust its aperture, shutter speed, or ISO to make the face the correct brightness, preventing it from appearing too dark.