The simplified formula of point calculation states that the illuminance E (lx) decreases by the square of the distance. Therefore, to maintain the same illuminance, four times the number of luminaires are required if the room height is doubled. The implementation of this simple physical law in the Quadra product range has given rise to models with single, double and quadruple lamps, this can be seen from the number of reflector cells for the low-voltage halogen reflector lamps. The outputs lumens can therefore be adjusted to suit different room heights or zones of different brightness levels.