... is always preferable to use one single channel insteadof a number of parallel ones since all parallel channels should behave identicallyunder all circumstances, and, practically speaking, that ... “onecandle.”Theoretically an ideal punctual source, that is a theoretical source shaped as a dot having no physical dimensions, radiates equally in all directions. The amountof light radiated ... two flat areas, one white and the other black, separatedby a sharp, straight transition until, at three-quarters height, the line becomes saw-toothed. At a relatively short distance away, the...