By selecting the ratio of diffuse to directed light, lighting designs can control the degree to which shadows give shape to forms and textures. Diffuse light comes from the daylight of an overcast sky or from a diffusely emitting luminaire. On the other hand, sunlight, spotlights or wallwashers with point light sources produce directed light casting harsh shadows.
The diffuse daylight entering the room creates a very soft atmosphere. The objects and room surfaces have very little shadow, indicating that there is hardly any shaping effect. The surfaces appear soft to the touch and the sculpture only makes a very soft and discreet shadow on the wall. The furniture almost seems to be floating above the carpet since no shadow connects it to the floor. A small amount of directed light from the left casts a slight shadow on the back wall.
The combination of diffuse and directed light creates shadow pictures which consist of both hard-edged and soft shadows. The large, diffusely illuminated light panel on the rear wall produces a softer light than the pendant luminaire and therefore gives the heavy shadow an even softer progression. The harsh shadow behind the sculpture is due to the directed accent light from the ceiling spotlight. The diffuse light from the wall-mounted downlight and the directed light of the spotlights overlap in the area of the seating.
Through the diffuse lampshade the pendant luminaire with its large illuminated surface produces a soft light that prevents sharp-edged shadows. Yet at the same time, the shadows formed by the furniture and sculpture indicate that the lighting situation also has an inherent direction that gives shape and form to the objects.
The directed light of the sun and the spotlights creates a high-contrast interplay of light and dark with crisp shadows. The objects cast shadow on themselves, thereby accentuating their three-dimensional appearance. The heavy shadow on wall and floor creates a greater link between the objects in the room and their surroundings and also accentuates the contours. Whereas a narrow-beam spotlight will often only cast a single shadow, wider beam angles will frequently produce overlapping beams and multiple shadows. Depending on the illuminance and the distance to the luminaire, this results in silhouettes of varying intensities.
