What Is a Digital Light Meter?

A digital light meter is a device used to measure the amount of light in one area via the use of a digital readout meter. Most digital light meter units are able to measure up to 5,000 foot candles, and the measuring unit is typically separate from the meter itself for easy manipulation and for better measurements. Light measurements are needed by photographers, farmers, gardeners and moviemakers to ensure that the best lighting is used for the shot or plant. If a certain lamp is being used, such as a mercury lamp, the light measurement might need to be adjusted.

When it comes to needing an exact measurement of light, it can be very difficult to take an accurate measurement with sight alone. To ensure accuracy, a digital light meter is used. Most meters consist of two parts: the meter and the measuring unit. The measuring unit is placed on the ground, with a sensor facing the light source. The meter itself displays the foot candles.

All digital light meters record light in a measurement called foot candles. A foot candle is defined as how much one lumen of light would illuminate a surface that was 1 square foot (929 square centimeters). The common amount of foot candles that a digital light meter can measure is 5,000 foot candles, but some meters might have higher measurements.

Measuring light to the exact foot candle might seem unnecessary for most people, but there are a few industries and people that need this measurement. Photographers, who want to achieve a certain shadowing effect, need a specific amount of light. The same goes for moviemakers, because the amount of light can enhance or destroy a shot. Farmers or gardeners might need to measure light as well, because some plants will not grow if the light is too dim or intense. This is mostly if the farmer or gardener is using a lamp or artificial light source, because these sources can be changed and calibrated, but the sun cannot be.

If a lamp is being used, such as by a photographer or gardener, the light measurement might need to be altered, depending on the lamp type. The digital light meter’s manual will detail any lamps that need the measurement altered. For example, if a mercury lamp is being used, the foot candles typically will need to be adjusted by 0.1 to make the reading accurate. The range of the light source might also require that measurement be altered, depending on the meter, to make the light reading accurate.