Light Meters General Info Light Meters General Information Light can be quantified in many ways, i.e., Lux, Lumens, Footcandles, candle power, candelas, and so on. The two most popular scales are Lux, which is the European measure, and Footcandles which is the U.S. scale. Lux is a unit of illumination of one square meter which is one meter away from a uniform light source. Footcandles are a unit of illumination of one square foot which is one foot away from a uniform light source.
Most meters consist of a body, a photo cell and a readout.
The light that falls on the photo cell has energy. The meter then reads the electrical current and calculates the appropriate value of either Lux or Footcandles. The reading, therefore, is a result of the combined effects of all the wavelengths. A standard color can be referred to as color temperature and is expressed in degrees Kelvin. The standard color temperature for calibration of most light meters is 2856 degrees Kelvin which is more yellow than pure white.