Searchlights have been around for over a hundred years. Through most of their history they have been used mainly for war applications. In World War I, prior to the wide spread use of airplanes, they were used to simulate light on the nighttime battlefield. During World War II, due to the wide spread use of airplanes for warfare, searchlights were pointed towards the night sky as a means of detecting enemy aircraft.
Before WWII, their non-military use had been limited to very large events; such as, the 1933 World's Fair. In these types of events they weren't really used as promotional tools, but were more like giant oddities. It would not be until after World War II that the power of searchlight lights would be more widely used for their promotional properties.
From the end of World War II through to the early 1970s promotional searchlights were actually refurbished mothballed military searchlights. The refurbished military searchlights used large carbon arch lamps, producing massive beams of light that could be seen for up to 25 miles away. These lights were definitely attention grabbers. But, because they were so large their use, for promotional purposes, was not very wide spread and was limited to events that could accommodate their size.
In the 1970s there was a revolution, of sorts, in lighting technology. The new types of light bulbs (more formally called lamps) used new types of chemicals to create similarly powerful light beam, but from a smaller light source. The availability of smaller lamps meant that the overall size of the searchlight was reduced considerably.
The smaller size requirements enabled the first true promotional searchlights, that could be used on a wide scale, to be made. The use of promotional searchlights was no longer confined to large events such as fairs and carnivals. They could now be used for smaller events like restaurant and nightclub openings or for special retail store promotions.
Since the 1970s, a wide variety of powerful light source technologies have been developed. Most of the technological evolution has focused on creating whiter denser lights that require smaller and smaller amounts of electricity. Because, the light source has become smaller and the power requirements have decreased, over time, the use of promotional searchlights have increased, over time.
From the 1980s until today lighting technologies have continued to evolve. Now there are any number of possible light sources that can be used for a promotional searchlight. What type of light source is used is only limited by the cost price point of the particular brand of searchlight. Although light source technology has played a huge role in the evolution of the promotional searchlight, programmable circuits have had the most recent impact.
With the development of programmable circuits and computers the promotional capabilities of searchlights have increased dramatically. Many of today's modern promotional searchlights contain special circuits, and even small computers, that enable them to, turn in a synchronized fashion, change the color of the light beam, and even be controlled remotely.
What started out as a promotional gimmick, at the end of the 1940s to promote Hollywood movie premieres, has grown into an industry in its own right. Evolution of lighting sources and circuitry has enabled these lights to be made smaller and smarter. The maturing of promotional lighting technology has opened new possibilities for the industry. As the technology continues to evolve so will the possibilities.