Selecting the best bulb shape
Updated June 4th, 2015
Not many people study Christmas lights. Most people pull the lights out of the closet or attic sometime around Thanksgiving, hang them on the Christmas tree, or drape them over some bushes, and then take them down after New Years. If you are thinking about replacing those old incandescent lights this year with energy-efficient LED string lights you may be surprised at all the options available. There are differences between the options, and it is good to know a little about the choices available before you go shopping.
Christmas style LED lights are offered with a wide variety of bulb shapes and sizes. The most common bulb types are the 5MM or conical, G12 or raspberry, M5 or mini light, C6 or strawberry, and the more traditional C7 and C9 bulbs. 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 inside does not vary in size regardless of the bulb shape. Thus, the largest C9 style LED Christmas light contains an LED chip that is the same size as the one inside the smallest 5MM style LED Christmas light.
Another significant difference between the function of the bulb in LED Christmas lights, and standard incandescent Christmas style lights, is the color and texture of the bulb material. Incandescent holiday lights create different colors by using tinted or painted glass, which can fade or chip. LED holiday lights produced colored light by using different phosphor blends in the LED chip. Although most LED lights for Christmas decorating have colored bulbs, this bulb housing color, 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 if used outdoors. Because the color of the LED light is not determined by the bulb cover color, this is not an issue with LED lighting, and the colors will stay brighter and truer for longer. Most LED lights designed for Christmas, holiday, or decorative lighting, will 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 project 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, so that it appears equally brilliant from all angles.
Because the bulb essentially just acts as a cover or lens in LED string lighting, its main purpose is to give the bulb “shape” and to diffuse the light. Generally speaking, all bulbs will be the same “brightness”, however the smaller style LED bulbs appear to be the brighter than the larger shaped bulbs, as the LED inside has less space and plastic to fill up (appearing brighter).
Now that you know a little bit about the function of a LED Bulb, let’s discuss where to use each shape:
5MM or conical Bulb Style – This is the smallest, and one of the newest bulb styles offered in LED holiday lighting products. It’s small uniform shape allows for even light distribution in all directions, no matter which way the bulb is pointing. The 5MM is one of the most versatile bulb styles, and can be used for pretty much anything (rooflines and large trees would be the exception). It is the preferred bulb shape for branch wrapping trees, but also works great for lighting bushes, small to medium size trees, lighting railings or posts, or is great for your indoor Christmas Tree.
The 8MM is another variation of this bulb style – It will be slightly larger than the 5MM (wider and taller), but it’s uses will be the same.
G12 or raspberry Bulb Style – This is one of the original bulb shapes offered in LED holiday lighting products. Its small round shape allows for even light distribution in all directions, no matter which way the bulb is pointing. The G12 is also very versatile, and can be used for the same applications as the 5MM bulb style. They are especially nice on garland or wreaths, as they look like little lighted berries. The light emitted by the G12 bulb style will be slightly larger in size than the 5MM, so if you are looking for something that will take up a little more “space”, the G12 would be a great choice.
M5 or mini light Bulb Style – This bulb style was introduced to fulfill a demand for a bulb that looked more like the traditional Incandescent Mini Light. The M5 will have an elongated shape, which does not lend itself well to branch wrapping, but gives a more “traditional” look than the other bulb styles. You can use the M5 bulb style anywhere you were using incandescent mini lights, including but not limited to, your indoor Christmas Tree, garland, wreaths, bushes, or small to medium size trees.
This bulb style is also offered with a smooth finish in the Color-Rite line – Looking for something that looks just like an incandescent Mini Light? Check These Out!
C6 or strawberry Bulb Style – This bulb shape is similar to the traditional C7 shape, but will be slightly smaller. The C6 is what we would consider a medium sized bulb, and it fills a nice niche - where the M5 may be too small, and the C7 may be too big. They are great for medium to large conifer trees, and are perfect for medium to large wreaths, or garland - as they look like little lighted pine cones. The C6 is a great choice for your indoor Christmas Tree Too!
The C5 is another variation of this bulb style – It will be slightly smaller than the C6 (width and height), but it’s uses will be the same.
C7 or C9 Bulb Style – These bulb shapes will be the same as their Incandescent counterparts, and thus can be used in the same locations. C7 and C9 Bulb styles are generally kept to roofline applications, but can also be used on large trees. Their large shapes are generally better suited for larger items, but if you are looking for a safer and more energy efficient option to the old glass incandescent bulbs, you could even use them on your indoor Christmas Tree.
Less Common, or Specialty Bulb Styles include the Cherry Blossom, G-Series - (G30, G40, and G50), and S14 bulbs. These bulbs do not have a traditional “Christmas bulb” shape, so they work great for non-traditional decorating, or even summer or patio lighting.
General Rule of Thumb – Correlate the bulb size with the size of the item you are decorating – Larger Item = Lager Bulb Shape – Smaller Item = Smaller Bulb Shape