- These are two terms that are usually used interchangeably by photographers. Both are devices for measuring light, however, technically a “light meter” only reports the light’s intensity, whereas an exposure meter measures the intensity of light and translates that data into camera settings needed to make a correct exposure in the given lighting situation. There are two types of exposure meters - incident and reflective. The exposure meter built into your camera is a reflective light meter, meaning that it measures light reflected from a subject. The other type of exposure meter, incident, measures light that falls directly onto the meter. This is the type of meter that is used to measure flash’s intensity.
Exposure Meter or Light Meter