Definition that contains point source
- lm a unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directions
- lumen a unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directions
- footcandle a unit of illuminance on a surface that is everywhere 1 foot from a point source of 1 candle