Low-Voltage Contrast & Fixture Selection

By Nate Mullen, from Advanced Trade Secrets of Professional Landscape Lighting, reprinted with permission.

Low-voltage fixtures are not toys, but they do come with an exciting array of styles, colors and effects. This lighting manufacturer's exhibit shows off some of the diversity of lamp types and fixtures available. The photo was taken at California-based manufacturer's booth at February's California Landscape Contractors Association show in Los Angeles. Photo by Erik Skindrud

Relationship of brightness, or levels of light from one object to another or visual field to visual field, is the key that lets a lighting designer create depth, focal points, triangulation, framing, dimension and many other schemes. This relationship is crucial to the overall lighting portrait. When done properly, it will allow the eye to be directed through the portrait, establishing different points of reference and interest.

A number of fixtures similar to those in the adjacent shot are used in this night landscape. Turkish lighting designer GŸrol Ayan sought to create a harmonious connection between this home and its landscape using lighting. Multiple spotlights with spike halogen lamps are placed at different angles. Green LED step lights (like the one to the left of the turtle in the accompanying photo) can be seen along the walking path. The project location is Omerli in Istanbul, Turkey.

The photo emphasizes a lighting effect called "mirror lighting," where the object is lit up behind a surface of water, which is then reflected back to the viewer. To achieve this effect, the water element must be dark and still -with no motion on the water surface. The design team utilized a total of eight light fixtures in this shot. Two up-lights cross-light the specimen tree, while a single down-light was used to pick up the lawn-path area in the foreground. A total of three path lights were used along the planters of the pool deck and two washing lights were used to gently wash the taller hedge of shrubs at the left end of the pool.

Measuring Light

Defining a particular level of light as bright, medium, or dim can be confusing unless there is surrounding light to use as a reference. Bright and dim compared to what, I always like to say, because in reality it is only the apparent brightness that we see. This is why a low level of light can appear to be brighter than it really is because there's no surrounding light for reference. Also, people differ in what they perceive as bright and dim. It all s on age, time of day, whether you're indoors or out, the surrounding light intensity, and what you are accustomed to. But we do need some sort of understanding and measurement on how to determine a certain level of light. The scientific way to do this is actually measuring the level of light reflected from a surface in Foot Lamberts. An easier way is to compare the Levels of Light between each of the visual fields or objects on your lighting job.

Low-voltage bullet lamps at left in this view contrast with their larger line-voltage cousins at right in this view. Line voltage can result in serious injuries or worse and is generally installed by licensed electricians. Photo by Erik Skindrud

Lighting designer GŸrol Ayan decided to emphasize this home with more powerful line voltage lamps so it wouldn't be lost against the urban skyline. The wall-mounted luminaries at right are customized using lenses. For the landscape, low-voltage spots with spike halogen lamps highlight trees and shrubs. This home is at Kurucesme in Istanbul, Turkey. Photo courtesy of Studio Dekor

It's important to understand that Levels of Light are not preset according to any particular standard. For example, Level 1 does not necessarily mean five foot-candles, Level 2 doesn't have to be 10 foot-candles, etc. The actual brightness of each Level of Light will differ from job to job depending on the apparent brightness between your visual fields or objects, which will either be connecting or contrasting.

These wall-sconce lamps play up the depth and texture of the surface while at the same time creating a pleasing pattern of light. The lamps also define the ground, assisting guests who sit at this outdoor bar and barbeque.

Plant material, surfaces and textures, and the size of the yard also will help determine this relationship. Level 1 is generally achieved from the primary light in Level 2 and 3 areas hitting surfaces and bouncing back to illuminate paths or walkways with the resulting ambient light. Additionally, depending on color and surface texture, this ambient light can also bounce to another surface.

Level 1 is also used when you want dim lighting to fill in dark areas or to provide secondary perimeter or boundary lighting. Here, the use of lower wattage lamps or lenses and screens are appropriate to tone down the intensity of the lamp. Placing lamps further apart is not the answer, as doing so would only create black holes between fixtures and the apparent brightness would be brighter in the area lit. Levels 2 and 3 are achieved through proper fixture placement and technique and generally not through higher or lower wattage lamps.

Wall-sconce lamps like this model direct light in an up-down beam spread. This Orion fixture's brass body is ideal for small niche areas. Available in 4-inch or 6-inch heights, these wall sconce fixtures are equipped with 20-watt Astro-Brite, 10,000 hr. Xenon lamps and 25 ft. of low voltage wire. Photo courtesy of Ethan Hauck, Unique Lighting

The key here is to provide adequate contrast. This is the best way to distinguish the light relationship between your visual fields. The main issue here is to provide contrast. Think of providing contrast by having separate visual fields or frames. You can have either connecting fields or contrasting fields. A connecting field is when the light between objects or the objects themselves appear to be at the same light level. It can be any level of light, whether 1 to 1, 2 to 2, or 3 to 3.

Sam Barker, Jr. of Santa Ana, Calif.-based Sebco Industries demonstrates a bank of MR16 low-voltage lamps connected to one of the manufacturer's lighting transformers. Transformers are a key component for low-voltage lighting, converting standard 120-volt line voltage to 12-volt power. Each transformer has a specific total voltage load that cannot be exceeded without risking component failure. Photo by Erik Skindrud

In these cases, it doesn't matter because there's no contrast. The areas appear to be connected. A contrasting field is just that -there is contrast around that area. What really matters is that a change in light levels is perceived between visual fields, whether from darker to lighter, or lighter to darker. The contrast could also lie in the color or density of the material. You just need contrast.

A mixture of up and down lights can work together to draw the eye through the setting. The goal is to create depth through the layering process. The design team sought to make the background elements the strongest (up lights on the oak trees behind the pool) with the mid-ground areas illuminated with more subtle down lights. The landscape is spread over 80 ft., so it was necessary to break up the back areas of the pool with shadow and a softer play of washing lights at the pool edge planter. Note the beautiful pools of light blanketing the lawn areas from the oak-it was decided that this approach was better than sticking path lights in along the walk out to the patio. Photo courtesy of Douglas Hooper, Avalon Artistic Landscape Lighting

In addition to proper placement there are several other ways to achieve contrast. First, you need to understand that light reacts in different ways when it hits a surface, and an awareness of the different types of surfaces you're likely to encounter is very important.

Bullet lamps are the indispensable tools that let landscape lighting designers illuminate trees and architecture from below. Bronze bullet lamps like the one on the opposite page are easy to hide in planting beds, as seen at left. Fixtures like the one in the above photo are designed to up-light from hardscape positions. Photo courtesy BTS Landscaping Inc.

You can tell the difference between contrasting fields in ratios of Level 2 to 1. The ratio of 3 to 1 can become a focal point. Ratios above 4 or 5 to 1 can become too dominant of a visual force, create hot spots, and are usually not recommended (like brass and glass front door fixtures). Contrast is generally not achieved by using higher or lower wattage lamps. The reason for this is that if you are lighting up a small shrub or tree, a 20-watt lamp is just as bright as a higher wattage lamp. Just shine a flashlight on an object as you stand close to it and you'll see what I mean. The effect is really apparent when the fixture is close to the object.

In-ground fixtures like this Nova can up-light trees, shrubs, pillars and other vertical structures. The fixture works with a standard 20-watt MR16 and a 4,000-hour halogen lamp. Image courtesy of ethan hauck, unique Image courtesy of ethan hauck, unique

Rather, contrast is more a function of the amount of light arriving at the object's surface, dictated by its distance from the fixture. This is why lamp photometrics, provided by manufacturers, are so important. The further you move the fixture away from the object, the less light you'll have on it.

This is where the inverse square law comes into play. This law states that when you double the distance from the fixture to the surface, you use one quarter of the light-which means you have now reduced the light by 25 percent.

Small bullet lamps like this are helpful when up-lighting is challenged by a small installation area. This Probe fixture is enhanced by a ball-and-joint swivel mount that allows 360-degree rotation. The brass body houses a MR16 35-watt halogen bulb. Interchangeable lenses can help installers customize this lamp's effect. Photo courtesy of Ethan Hauck, Unique Lighting

My whole philosophy is based on this premise: lighting up enough surface area to get reflected light from the landscape or structure. This will give you the different levels of light required to enjoy the property while providing safety and security. Think of it like this. If you turn on a table lamp with a 60 watt bulb in it, that one bulb will cast light over the whole room because of the reflected light from the walls. Dark-colored painted walls will obviously reduce the reflective value of the light emitted from the lamp. White walls will increase it.

New Jersey-based BTS Landscaping, Inc. added lighting to their line of services in 2001. This home is lit with 11 Cast bullet lamps fitted with 35-watt bulbs. A total of two transformers were used on the job-one 1,200-watt and one 900-watt. The tree at left here is a paper bark maple (Acer griseum) and is lit with two well lights using PAR-36 lamps, both with protective lenses to protect against leaf litter. Photo courtesy BTS Landscaping Inc.

Establishing relationship of brightness is one way to help you figure out the reflective value of light given off a surface. Learning the reflective values of the objects you're lighting up is an important step in your lighting proficiency. Some plant and building materials reflect light better, while some suck up light like a black hole in space.

I always try to take advantage of the plant material on site. It's a great way to provide contrast. Just remember, contrast is the key. And you get contrast through color, density and placement of fixtures, technique, and surface texture. By adding this know-how to your tools as a lighting designer, you will be able to walk onto any site, use the home and landscape as a canvas, and paint a lighting portrait.

The lighting scheme here focuses on the unique bell centerpiece, with a backdrop of mood-enhancing light spilling down from the oak behind. The intimate setting used a total of seven light fixtures. The design is made up by a single path light at the steps, one down light onto the bell from the tree, and two down lights filtering through the oak into the surrounding planters. The design team picked up the distant background with a single up light on the far oak and a pair of down lights into other planter areas. Photos courtesy of Douglas Hooper, Avalon Artistic Landscape Lighting

Lighting Fit for a Princess

Color-controllable, high-power LED lighting is one of the most impressive lighting technologies in use today. With separate red, green and blue diodes (the primary colors), the lamps can be programmed to cycle through color changes over a period of seconds, minutes or hours. The system runs with a DMX controller-the kind of unit also used with stage lighting.

For the April issue, LCN received more than 80 high-resolution submission photos from across the U.S. We also were pleased to receive a batch of impressive photos from the Studio Dekor, one of the biggest lighting design and installation firms in Turkey.

During the reign of her brother Mahmud she was one of the richest women in Constantinople.

The lighting is programmed to cycle from yellow-orange to blue to the red seen here. High-power LED fixtures are prized by industry pros for their color range and narrow beam angle. These fixtures (at bottom) are manufactured by the Italian firm Space Cannon. A team of one technician and two workers installed the system in five days. Photos courtesy of …zlem F. Celik, studiodekor.com

Esma Sultan briefly became a candidate for leader of the Ottoman Empire when her brother Mustafa was murdered in 1807, before completing his first year in power.

Sources: Wikipedia, …zlem F. Celik, studiodekor.com

Using Levels for Contrast

Subtly varying light levels are the key to creating contrast on the many surfaces in a nighttime landscape. A lamp with a specific wattage will create more or less light depending on its distance and the reflectivity of the surface it illuminates. Image courtesy of Nate Mullen, Unique Lighting

LEVEL 1: Low level. Use this level for pathways, sidewalks, driveways, and to fill in dark areas or black holes and in certain areas to extend the space and define boundaries.

LEVEL 3: Highest level. Use this level for focal points and depth, anchor points, entries, sub-scenes, and any area in the yard that you want to make visually active (or draw attention to).