Measuring Light Intensity
The cinematographer must consider light in five different ways—how much (intensity), what kind (quality), what color (color temperature), how it falls (direction), and how many sources (balance). The most basic skill in cinematography involves measuring and controlling the quantity or amount of light reaching the film.
The science of light measurement is called photometry. The standard unit for light measurement was originally based on the visible radiation of a single candle, called the standard candle. The old standard candle has been superseded by the candela, which ...