What is a light meter primarily used for?

A light meter is primarily utilized for measuring the quantity of illumination, which is critical in various applications such as photography, cinematography, and workplace safety assessments. It quantifies the intensity of light in a given area, typically expressed in lux or foot-candles. This measurement helps ensure that an environment has adequate lighting for tasks, enhances safety by reducing the risk of accidents due to inadequate visibility, and supports compliance with occupational health standards.

In contrast, the other options relate to different types of measurements: sound levels pertain to audio environments, temperature variations deal with heat measurements, and air quality evaluations focus on assessing the presence of pollutants or contaminants in the air. Each of these areas requires specialized instruments distinct from a light meter, reaffirming that the primary function of a light meter is to assess light intensity.