lux vs. foot-candle

lux

[luhks] / lʌks /

noun

Optics.

a unit of illumination, equivalent to 0.0929 foot-candle and equal to the illumination produced by luminous flux of one lumen falling perpendicularly on a surface one meter square. lx

foot-candle

[foot-kan-dl] / ˈfʊtˈkæn dl /

Or footcandle

Optics.

a unit of illuminance or illumination, equivalent to the illumination produced by a source of one candle at a distance of one foot and equal to one lumen incident per square foot. FC