Measures of Light Output
Three units are used to measure light output. Manufacturers do not always quote the most appropriate figure—for example, watts are commonly quoted, but wattage alone is a poor measure since (a) it reports the consumption of power rather than the output of light, and (b) lamp optics will significantly impact the portion of the light which is delivered where it is needed, for example concentrated in a spot beam or dispersed as in running lights. Candelas, measuring the intensity of a beam, are more appropriate when the aim is to illuminate brightly a small spot, while lumens, measuring the entire production of light, are more relevant to the purposes of broad beams or non-directional running lights.
Read more about this topic: Bicycle Lighting
Famous quotes containing the words measures of, measures, light and/or output:
“There are other measures of self-respect for a man, than the number of clean shirts he puts on every day.”
—Ralph Waldo Emerson (1803–1882)
“the dread
That how we live measures our own nature,
And at his age having no more to show
Than one hired box should make him pretty sure
He warranted no better,”
—Philip Larkin (1922–1985)
“For eighteen hundred years, though perchance I have no right to say it, the New Testament has been written; yet where is the legislator who has wisdom and practical talent enough to avail himself of the light which it sheds on the science of legislation?”
—Henry David Thoreau (1817–1862)
“Lizzie Borden took an axe
And gave her mother forty whacks;
When she saw what she had done,
She gave her father forty-one.”
—Anonymous. Late 19th century ballad.
The quatrain refers to the famous case of Lizzie Borden, tried for the murder of her father and stepmother on Aug. 4, 1892, in Fall River, Massachusetts. Though she was found innocent, there were many who contested the verdict, occasioning a prodigious output of articles and books, including, most recently, Frank Spiering’s Lizzie (1985)