What is the purpose of metering with a gray card in lighting setups?

• A. It provides a standard reflectance to help meters set correct exposure.
• B. It directly sets the camera's white balance.
• C. It determines the scene's color temperature.
• D. It serves as the main light source.

Answer: (A)

Metering with a gray card provides a standard reflectance that your light meter can read. The standard reference, usually 18% gray, gives the meter a known light level to measure against, so it can calculate exposure settings (aperture, shutter, ISO) that render neutral tones accurately across the scene. This helps prevent overexposed highlights or underexposed shadows when the lighting on the subject varies. The gray card is mainly about getting the right exposure; while you can use a neutral gray card to help with white balance later, its primary role in metering is not to determine color temperature. It doesn’t provide light or set the camera’s white balance by itself.