observation zone, size of picture and optimal viewing angle (fig. on left) are the parameters defining the optimal position of a wall-lighting luminaire.
The upper edge of the picture determines the spotlight opening angle (B: 30°, C: 60°) with a constant angle of inclination of 30°.
Angles less than 30° canresult in reflections at the upper edge of the picture (critical observation zone).
The mathematical formula for calculating the distance “x” between spotlight and wall for illuminating a picture with the height “y” is: x = y tan 30°