A fluorescent light, for example, casts as much as 900 foot-candles
of light, but that's only within 6 inches of the light bulb.
By changing that, we were able to get the foot-candles
up to 25.
of horizontal illumination on the ground and 0.
We recently conducted a research project in which the dining room provided only five foot-candles
of light at the table, which is well below the 50 foot-candle
At the meeting George Brainard (Thomas Jefferson University) demonstrated how our body stops producing melatonin --an important hormone that affects sleep, aging, and reproduction--when exposed to even a tenth of a foot-candle
of certain wavelengths of light.
The problem is that when local TV wants to broadcast a basketball game, the 50 foot-candles
aren't always enough.
are the measurement of light on the vertical plane with the meter held horizontally.
It is important that the ambient illuminance not exceed recommendations for spaces with video display terminals (VDTs), 25 to 50 foot-candles
of uniform ambient lighting.
, cadets correctly identified an object only 4 times; they misidentified or said they could not identify an object 44 times.
Throughout the store, lighting levels have been increased from the traditional a foot-candles
to 52 foot-candles
Having obtained the number of foot-candles
, the next step is to determine the spacing of the lamps and their height.
Apparently no one has studied this intriguing question, but we do know that the intensity of white light has to be at least 40 foot-candles
(lux), and that an average of 100 lux for 16 hours will stimulate body growth and milk production in dairy cattle.