In the left half of the left plot, specific illuminance by a continuous row of luminaires spaced 5 heights is shown (right half is for a single luminaire). | The right plot is for a single luminaire, unrotated. |
Values below the scale are illuminance / 1 lx. This is for (unrealistic) “unit” case that luminaires would have lamps producing 1 klm only, would be point-like and just 1 m over the terrain.