Certified Professional Photographer (CPP) Practice Exam

Which type of meter gives an average value for 18% gray?

1. Incident

2. Reflective

3. Spot

4. Average

The correct answer is: Reflective

The type of meter that provides an average value for 18% gray is reflective metering. This is because reflective meters measure the amount of light that is reflected off the subject and are designed to interpret that reflected light as an average scene tone. Many reflective meters are calibrated to determine exposure based on the assumption that most scenes average out to 18% reflectance, which is a standard mid-tone often referred to as 18% gray. While incident meters measure the light falling on the subject, they are not tied to the reflectance values of specific surfaces. Spot meters measure a small area of the scene, providing a reading that may not accurately represent the average tone of the entire subject unless carefully used to sample various parts of the scene. Average meters, though they may seem relevant, are not typically categorized separately in the context of standard photographic exposure metering. Therefore, reflective metering stands out as the option that directly relates to achieving correct exposure based on the average of 18% gray.