Exterior lighting is a well-choreographed mix of safety, security and art. Although there are some shared features, exterior lighting actually has little in common with interior lighting. Landscape lighting can be more easily likened to theatrical lighting than interior lighting. Texture and drama are added to what is illuminated while the shadows can conceal what is unsightly. Done right, landscape lighting is the perfect combination of function and art.
It is important that your exterior lighting achieves the right contrast between light and dark areas. Many different lighting techniques exist that can be used in combination with one another to accomplish this task.
One such technique is decorative lighting. Decorative lighting is generally used to provide task or ambient light. This particular type of lighting is commonly used to light pathways.
Accent lighting is used to highlight architectural or landscape features such as rock walls or trees. Strategically placing hidden lights around plants and architectural focal points can selectively illuminate these features. This technique is most powerful when only the illuminated item is seen and the fixture producing the light is well hidden.
Backlighting is another landscape lighting technique. Backlighting illuminates an object from behind and often from above where it is located. With this technique, an object can be silhouetted against the background.
Frontal lighting involves using one or more angles, either from the top or the bottom of the object, to illuminate the object’s front. Frontal lighting can be combined with backlighting to visually pull an object out from against the background. Another frontal lighting application is grazing. With this technique, a light source is placed closely above or below the object’s surface. This light produces rich shadows in highly-textured materials such as rock or brick. The closer the light source is placed, the more dramatic the shadows it creates.
Downlighting, or moonlighting, is yet another technique common in landscape lighting. Moonlighting involves placing light sources up high in trees with the light directed down toward the ground. This creates a soft, shadowy light that mimics that of moonlight. The higher the light source is placed, the greater the effect and the more diminished the light levels are on the ground.
Fixtures and bulbs
Once the design has been completed, it’s time to pick out fixtures. When choosing fixtures for decorative lighting, almost any kind of exterior decorative luminaire will suffice. It is important, however, to keep in mind that the top priority with all types of exterior lighting is to avoid glare. Lantern-style fixtures cause glare as they spill the light in all directions. Many designers these days are completely avoiding the use of lantern style fixtures and instead opting for fixtures with hoods that hide the bulb of the fixture. Exposed light bulbs cause glare. With decorative fixtures, position of the fixture and shielding of the bulb are important considerations in preventing glare.
With all of the other landscape lighting techniques, the focus is on the light produced by the fixture, not the fixture itself. For these techniques, in-ground luminaires, floodlights and bullet luminaires are commonly used due to their ability to be concealed and easily direct the light they produce. These types of fixtures can be hid by placing them deep into plants or other landscaping materials.
Choosing the right light bulb is just as important as the fixtures themselves. Always choose low-wattage light bulbs. High wattage bulbs do not provide any more security or appeal to the landscape, they only result in higher energy costs. If more light is needed, adjust the color or kelvin (K) value of the light bulb rather than the wattage. Consider using different colors or kelvin (K) values for different types of lighting. For example, 2700K light bulbs are often used for general seating to promote relaxation and make the space inviting. The 3000K light bulbs are often best for uplighting plant material, however 4000K really pops the color of a blue spruce. The 4000K light bulb is also a great light color for downlighting or moonlighting as it closely mimics the 4100K color of light that is actually emitted by the moon.
Lastly, try to minimize the use of uplights in your landscape design as they can add to light pollution. In some areas of the country minimal use of uplighting is mandated by code. Also, make sure the light levels in the different areas lit are subtle. Just as glare can be hard on the eyes, so too is moving from very bright areas to unlit ones.