Outdoor lighting provides a beautiful, aesthetic extension of your interior. Floodlights or spotlights focussing on the outer wall can create an extraordinary atmosphere around your home. Different results can be obtained by varying the distance between the spotlights from the wall and the spacing between the spotlights themselves. Do you want a uniformly illuminated wall or would you prefer separate patches of light on the wall? The following are a few guidelines to achieve the best lighting result by adjusting the distance, beam angle, wattage, etc.
What are floodlights?
Floodlights are directional spotlights that are fixed on a mounting box or installed on a ground spike or screw clamp for various purposes. Of these, ground spikes or screw clamps can be moved easily if you wish to adjust your exterior lighting. Installation on a mounting box and on a ground spike is the most commonly used method. Most spotlights cannot be installed on a screw clamp. Floodlights are therefore spike-mounted spotlights that provide concentrated directional light, often through additional reflectors.
Ground spots are also an option
Apart from floodlights, ground spots are also ideally suited for wall illumination. One advantage of ground spotlights in comparison to floodlights is that they can be driven and walked over at any time and therefore involve less hindrance. Moreover, they are not prominently visible during the daytime. The disadvantage is that they cannot be relocated once they are installed. On the other hand, it is much easier to relocate spotlights that are mounted on a ground spike or screw clamp.
What should be the distance between the spotlights and the wall?
If you want to accentuate the exterior of your home, you must first determine how far from the wall you can/wish to place the spotlight. The distance between the spotlight and the wall has an effect on the light and shadow effects created. And these are decisive for creating atmosphere.
Optimal results can be obtained by then selecting the appropriate beam angle, keeping in mind the distance from the wall. An appropriate beam angle should always be chosen keeping in mind the distance from the wall and the surface to be illuminated.
Placing a spotlight with a large beam angle far away from the wall is not ideal, since a large part of the beam can go to waste. In case of a greater distance, the beam angle required to illuminate the same surface area shall therefore be smaller than in case of a smaller distance. This phenomenon has been illustrated in the adjacent diagram. The beam angle shall expand as the distance increases.
Short distances to emphasise texture
If you place a certain spotlight close to the wall, the texture of the wall will be strongly emphasised. Every groove and furrow in the wall will be highlighted by the shadow and light contrasts. In case of a lesser distance, separate beams of light are visible on the wall in most cases.
Greater distances for uniform lighting
If you place the same spotlights further away from the wall, there will logically be less emphasis on the texture of the wall. A greater distance will also ensure that the individual light strips are less visible.
Uniform illumination or individual light patches
Uniform wall lighting
If you wish to light the outer wall evenly or uniformly, the spotlight should generally be placed further away from the wall. Of course, this does not always apply. You have to utilise the space available in front of the wall. And as stated earlier, a lesser distance more readily projects separate visible light beams on the wall.
The following illustration shows a wall 5 m wide and 2 m high, evenly lighted with four LED spotlights. Each of these spotlights has a beam angle of 40° and a consumption of 9 Watts. In order to achieve a uniform illumination of the wall, these spotlights should be placed at around 2.5 metres from the wall. A space of about 1.25 m is provided between the spotlights. In this manner, you will obtain an average lux value of 40 lx (unit of illumination) for the entire wall. An average of 40 lx is more than sufficient for atmospheric lighting. Even a small wattage can quickly produce results in the dark. The spotlights are located at a distance such that the light beams do not appear separately on the wall.
Lighting the wall unevenly
If you prefer separate light beams to be displayed on the wall, different distances should be maintained. In such case, place the spotlights closer to the wall and further apart from each other. With LED spotlights, this phenomenon is much easier than in case of other light sources. LED has strongly focused and defined light beams. This will quickly create lighting contrasts on the wall. CFLs are very diffuse and are therefore highly suitable for uniform illumination.
Suppose we wish non-uniform lighting on the wall in the previous example (width: 5 m, height: 2 m), the individual lighting surfaces must be visible. Let us now place the same four spotlights at a shorter distance of around 0.5 m from the wall. The space between the spotlights is still the same (1.25 m). If you place the spotlights further apart, you will obtain this separate result more quickly. Finally, the beam angle will change slightly.
The following illustration shows you that oval beams are now projected on the wall. The average Lux value over the entire wall is still 40 lx but the contrasts are now much greater. The difference in lux between the intensely illuminated point (centre of the light beam) and the least illuminated point (periphery of the beam) is now much greater than in the case of uniform illumination.
We therefore have to remember that a number of things determine the lighting of your outer wall. Depending on the type of outdoor lighting you desire, you may choose the distance from the wall, the distance between the spotlights, the beam angle, the consumption, and the light source. Each choice will have its own impact. If you use portable spotlights, you can play and experiment with light in order to obtain an attractive exterior.