>> 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.
The SI units for luminous flux are lumens, where a lumen is defined as a luminous intensity of one candela within a solid angle of one steradian. Luminous flux is often used to compare the lighting power of light bulbs.uminous flux is a measure of the perceived power of light or light intensity. Because luminous flux is the measure of a property in the perceived sense, it is adjusted to deal with the fact that the human eye is sensitive to many different wavelengths of light and in different ways.