Illumination refers to the amount of light that falls on a surface per unit area. It is typically measured in units like lux or foot-candles. Mean Spherical Candle Power (MSCP) is a term that relates to the distribution of light emitted by a light source in all directions, as opposed to just in one direction. It's a measure of the total light output of a source in all directions, averaged over a sphere.
To break down these terms:
Mean Spherical Candle Power (MSCP): This term is commonly used for light sources like bulbs or lamps that emit light in various directions. Candle power (or candela) is a unit that measures the intensity of light in a specific direction. MSCP takes into account the intensity of light emitted in all directions and provides an average value over the entire sphere surrounding the light source.
Illumination: Illumination is the amount of light that falls onto a surface area. It's measured in lux (metric) or foot-candles (imperial). One lux is equal to one lumen per square meter, and one foot-candle is equal to one lumen per square foot. Illumination takes into account the intensity of the light reaching a surface as well as the distance from the light source.
In summary, mean spherical candle power (MSCP) is related to the distribution of light emitted by a source in all directions, and it provides an average value of light intensity over a sphere surrounding the source. Illumination, on the other hand, measures the amount of light falling onto a surface area and is typically given in lux or foot-candles.