[header] How to measure light intensity [title] Understand photometers that measure lux and foot-candles. [step] These are units that describe the intensity of light on a surface, or. Photometers that measure this are usually what people are looking for when they want to set up a photo shoot, or test whether a room is too bright or too dim. 
[substeps] Some light meters are specialized for different types of lighting. For instance, one may produce more accurate results when used to measure sodium lighting.