>> Your prof was correct. Semantic domains, etymology, and all those >> little tidbits of trivia are interesting- but not useful in the final >> analysis because words gain meaning only from context. >[....] >> To isolate a word and assign it meaning is futile. >[....] > >There is more context to the text than the words proximate to >the text.
When looking at brightness specifications of LEDs, the most common specs available are luminous intensity (usually measured in units of candelas or millicandelas) and viewing angle (measured in degrees). The brightness of 1 candela is roughly around the same brightness as a common candle. A millicandela, or mcd, is 1000 times less bright than a candela, hence the prefix milli-. 1000 millicandelas = 1 candela. Since light is not always evenly dispersed, the viewing angle of a light source is very important.
Illuminance = Light Falling on a Surface. The amount of light falling on a surface is illuminance, and is measured in lux (metric unit = lumen/m 2) or foot-candles (English unit = lumen/ft 2).1 footcandle equals 10.8 lux.he amount of light that travels in certain directions from the source is called the  luminous intensity  and is measured in candelas. A candle emits about one candela in all directions (this candle would emit a total of 12.6 lumens â learn more about lumens, solid angles, and candelas on Wikipedia).