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:
“Those who, while they disapprove of the character and measures of a government, yield to it their allegiance and support are undoubtedly its most conscientious supporters, and so frequently the most serious obstacles to reform.”
—Henry David Thoreau (1817–1862)
“One encounters very capable fathers abashed by their piano-playing daughters. Three measures of Schumann make them red with embarrassment.”
—Alfred Döblin (1878–1957)
“And taken by light in her arms at long and dear last
I may without fail
Suffer the first vision that set fire to the stars.”
—Dylan Thomas (1914–1953)
“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)