Selecting the best bulb shape
February 13, 2008
Christmas style LED lights are offered with a wide variety of bulb shapes and sizes. The most common bulb types are the mini light, G12 or raspberry light, the C6 or strawberry light, and the C7 and C9. These bulb shapes are standard sizes that have been carried over from traditional incandescent Christmas lights. However, the function and purpose of the bulb is significantly different in LED Christmas lights than in incandescent holiday lights.
Incandescent Christmas lights use a variety of different bulb shapes mainly because it was necessary to house the larger sized filaments which were need to produce brighter lights. In contrast, LED lights do not use a filament and the LED light source does not very much in size regardless of its light output. Thus, a larger C6 style LED Christmas light does not contain an LED chip that is larger than the LED chip inside an LED mini light. In fact, in most cases the LED inside most LED holiday lights is exaclty the same size in all styles.
Another significant difference between the function of the bulb in LED Christmas lights and standard incandescent Christmas style lights is that color and texture of the bulb material. Incandescent holiday lights create different colors by using smooth tinted glass. LED holiday lights produced colored light by using different phosphor blends in the LED chip. Although most LED lights for Christmas decorating are colored it is not responsible for producing the colored light. This is a significant advantage because colored incandescent Christmas lights tend to loose color after a year or so especially is used outdoors. Because the color of the LED light is not determined by the color of the bulb this is not an issue with LED lighting. Most LED lights designed for Christmas, holiday or decorative lighting also utilize a bulb that is faceted rather than smooth. This is because the light produced by LEDs is highly directional and does not easily spread out in all directions like the hot glowing light produced by the filament of an incandescent Christmas light. The angles of the faceted bulb cover help to evenly distribute the light emitted by the LED holiday light so that it appears equally brilliant from all angles.
Because the bulb essential just acts as a cover or lens in LED string lighting its main purpose is to diffuse the light. Generally speaking, the smaller style LED bulbs are the most effective at diffusing the light evenly in all directions. The smallest bulbs also appear to be the brightest even though the actual lumen output is exactly the same as that produced by the larger bulb styles. The larger bulbs appear less bright because the larger bulb cover diffuse the light over a larger area. The larger bulb styles are also less effective at counter-acting the direction properties of LED lighting.
Accordingly, when choosing LED lights for your Christmas, holiday, or special occasion it is important to consider the effect you desire when choosing a bulb style. Remember, the larger bulbs will appear less bright and will not evenly diffuse the light. The largest bulbs such as the C9 may appear very dim from one angle and extremely bright from another. The smaller bulb styles produce the most even light distribution and appear to be much brighter.