The LED Spot Light: More than Just a Powerful LED|
Marine spot light technology appears to be one of the few areas in boat lighting where LEDs have yet to solidly cement their dominance. Part of this seems to stem from the common perception of LEDs as being effective luminaries, yet still lagging behind traditional lighting technology when it comes to the ability to project a light beam with plenty of throw. While it’s true that early attempts to produce LED spot lights capable of producing a light beam that rivaled traditional halogens for beam length were without a doubt less than effective, new approaches to how LED light is focused and projected have resulted successes that are nothing short of impressive.
When LEDs first began appearing in the mainstream marketplace, there were few manufacturers willing to take on the job of producing a spot light equipped with LEDs. Most offerings even close to resembling a spot light were relegated to handheld flashlights that produced adequate lumen numbers, but were unable to condense and focus LED light well enough to produce a true spot light beam. At first the problem was that manufacturers had yet to actually design reflector assemblies that could work effectively with LEDs. Most manufacturers seemed to assume that the tried and true reflector designs that served so well with incandescent and halogen lamps would in fact work equally well with the LED. In practice this turned out to be patently false, resulting in a great deal of disappointment on the part of consumers when LED offering failed to live up to their hype.
The reason LEDs work so poorly with normal spot light reflector designs is that these designs are intended to be paired with a single source of intense light. While LEDs are watt for watt far more powerful than incandescent lamps, a single LED is quite limited in the total amount of light it can produce. Thus, even the most powerful LED paired with the best spot light reflector is not going to be nearly as effective as a moderate incandescent lamp paired with the same reflector. In order for LEDs to be competitive, it is necessary to group them together in clusters and thus increase the total amount of light produced. This presents the problem of pairing these grouped LEDs with an effective reflector. If you look at any traditional spotlight, you will note that the reflector assembly is basically a cone that narrows down to a single point. This allows the assembly to evenly focus the light at a single point from the base of the cone and project it outwards. The angle of the cone will have great bearing on the tightness of the beam it projects, the tighter the cone, the tighter and more highly focused the light beam and the farther it will “throw”.
With LEDs in groups, there is no well centralized light source and designing a reflector capable of evenly focusing and projecting the light produced by this cluster is in fact quite difficult. While the degree of angle and circumference of the cone may be exact and even, the clustering of the LEDs results in a central light source with highly varied positions in relation to the reflector surfaces. The net result is a poorly focused light beam and weak light throw. Obviously, the old way of designing spot light reflectors is not going to be sufficient to capitalize on the potential of the LED.
In recent years some manufacturers have realized that the new technology LED lighting represents is going to require new light managing technology as well if LEDs are to be utilized to their true full potential. While much of the challenge with LEDs has until recently been getting more light out of a single LED, as LEDs become more effective the focus has begun to shift towards getting the light they produce to go where it is needed most. With spot lights the solution is almost as simple as the original spot light design. Rather than trying to cluster LEDs together and use a single reflector to condense and focus their light, designers have discovered that it is more effective to pair each LED with its own individual reflector. What has resulted is groups of LEDs each sitting in the center of a mini reflector which are then housed together in a single unit. The effect of this design is to efficiently intensify and focus the light produced by each LED while allowing the entire group to act as a single light source, essentially forming a single highly focused and powerful light beam.
One good example of such a design is the Larson Electronics LEDP10W-200X2E LED Light Bar which uses single LEDs, each paired with a reflector and then arranged in symmetrical rows and housed within a single unit. Such a design is easily capable of rivaling or even surpassing halogen spot lights for intensity and throw while still retaining the LED’s desirable ability to produce more light with less power. Despite the need for a multitude of LEDs to produce a powerful and far reaching light beam, power consumption is kept at low levels by the efficiency with which the light is focused. A peripheral benefit of such designs is that the heat produced by LEDs, although lesser than that produced by incandescent, is given a larger area over which to be dissipated. Since heat is the number one enemy of the LED, this is an extremely important consideration as LEDs used for high power and intense lighting applications like those found in spot lights tend to also produce the most heat.
The design that pairs each LED with a reflector is also highly versatile. Since each LED is in effect independently focused, the shape of their arrangement can be easily manipulated, thus allowing manufacturers to design configurations for a variety of specific applications with little or no loss of LED effectiveness. The strength and throw of the light beam produced by such arrangements is equally versatile as all this is needed is a change in reflector angle to produce either a wide flood or tight spot beam, or even something in between.
When considering an LED spot light, don’t be mislead by designs that continue to utilize outdated reflector configurations. Although the traditional single large reflector design is indeed effective with incandescent lamps, LEDs produce light differently and thus need a design tailored to their specific characteristics. When you see an LED spot light and find yourself wondering why the lamp is square or rectangular instead of round, know instead that what you are looking at is in fact likely a wisely designed piece of equipment.