Candela was chosen so that the new definition would precisely match the old definition. Although the candela is now defined in terms of the second (an SI base unit) and the watt (a derived SI unit), the candela remains a base unit of the SI system, by definition. If a source emits a known luminous intensity "I" (in candelas) in a well-defined cone, the total luminous flux "Φ" in lumens is given by where "A" is the "radiation angle" of the lamp—the full vertex angle of the emission cone. For example, a lamp that emits 590 cd with a radiation angle
Rosario Candela Rosario Candela Rosario Candela (March 7, 1890 – October 3, 1953) was a Sicilian American architect who achieved renown through his apartment building designs in New York City, primarily during the boom years of the 1920s. He is credited with defining the city's characteristic terraced setbacks and signature penthouses. Over time, Candela's buildings have become some of New York's most coveted addresses. As architectural historian Cristopher Gray has written: "Rosario Candela has replaced Stanford White as the real estate brokers' name-drop of choice. Nowadays, to own a 10- to 20-room apartment in a Candela-designed building is to accede to architectural