From this, it follows that at a measuring distance of 1 metre, the values for candela (lumen per steradian) and lux (lumen per m 2) are the same. Nearly all of the imagery available through the Planet API is available in a radiometrically calibrated format with unit spectral radiance.. The radiation intensity in a certain direction, in watts per steradian, is given by: For a certain direction, the radiation intensity will be maximal and equals: Radiated Power The total power radiated by the antenna, in Watts, is represented by: Effective Angle 2 In many countries, this unit is called "tonne.". Instant free online tool for candela/square meter to watt/sq. Candela/square meter ↔ Lumen/square meter/steradian Conversion in Batch. cm/steradian (at 555 nm) conversion or vice versa. Watt per Meter² per Steradian per Micrometer. source The International System of … Candela (cd), unit of luminous intensity in the International System of Units (SI), defined as the luminous intensity in a given direction of a source that emits monochromatic radiation of frequency 540 × 1012 hertz and has a radiant intensity in that same direction of 1683 watt per steradian (unit Or to be more accurate, it is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540×1012 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian. of a source that emits monochromatic radiation of frequency 540 x 1012 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian. Because "l" can easily be confused with the numeral "1," the symbol "L" is recommended for United States use. One steradian on a sphere with a radius of one metre gives a surface of one m 2 (see the section on candela). cm/steradian (at 555 nm) to other luminance units or learn more about luminance conversions. If the source has luminous intensity of one candela in each direction, a type of normalized "candle" ("candela" is a counterpart of one watt per steradian, but with the color/frequency-dependent weights corresponding to the human vision), then it emits luminous flux one lumen in one steradian. The scientific definition is “The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540×10 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.” I like my simple analogy better!! cm/steradian (at 555 nm) conversion table and conversion steps are also listed. 1 Both L and l are internationally accepted symbols for liter. Also, explore tools to convert candela/square meter or watt/sq. 3 The values of these units expressed in terms of SI units must be obtained by experiment, and are therefore not known exactly. ! candela (cd): The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 THz hertz (555 nm) and that has a radiant intensity in that direction of 1/683 watt per steradian. The candela is the luminous intensity, in a given direction. 1 cd/m2 = 1 lumen/square meter/steradian; 1 lumen/square meter/steradian = 1 cd/m2. It is the luminous power per unit solid angle emitted by a point light source in a particular direction. Candela/square meter: Lumen/square meter/steradian: Note: Fill in one box to get results in the other box by clicking "Calculate" button. The candela/square meter to watt/sq.