For God, creating light was as simple as speaking, but for mankind, that process is a lot more complicated. For us non-deity types, no matter the application when there is need for light, some level of human engineering is required. From the stone age where illumination in a dark environment was achieved only through a concentrated effort to make fire, to the more complex process involving the recombination of holes and electrons at the P-N junction of a semiconductor called a Light Emitting Diode (LED), the evolution of bringing light into darkness has evolved through the application of science and mathematics to provide mankind with the luxury of now taking it for granted. And take it for granted we have.
When you open a door to a dark room, you instinctively feel for the light switch. When you are driving at dusk and the daylight is fading, our modern cars automatically turn on the headlights. Buildings sense daylight to dim or turn off lighting when there is sufficient ambient lighting for the required task. We truly live in a complex, yet illuminating, world. But, despite all the technological advances that allow us to take it for granted, there is still a lot of hard science and engineering happening behind the scenes.
As simple as it is to flip a switch (or have one flipped for you automatically), illumination engineering has progressed far beyond the limitations of a simple On/Off constraint. Now, the hard engineering lies in understanding and developing more of the How, How Much, When, and Where of lighting. Search the web and you’ll find countless studies on the effects of lighting on the health, safety and general well-being of people and the environment.
What? Wait! Light is a good thing, so how can it also be a bad thing?
Too much light is bad, too little light is equally bad. Pointing the light in the wrong direction is bad. Light pollution is bad. Even the wrong color of light (color temperature) in a given situation can be bad. And not just “bad” in a general sense. In some circumstances “bad” can be down-right hazardous. Too much light and glare on a roadway at night in wet conditions can cause fatal crashes. Dim headlights prevent drivers from seeing hazards in time to prevent collisions. The same is true for pilots of aircraft and ships. Improper lighting can cause all sorts of problems. Headaches, migraines, nausea, dizziness, eye strain, vision problems, etc. Even for the cave man with his fire… too much or not enough could easily give way to “bad”, even deadly, situations.
Over the decades since the illuminating properties of fire was first observed, mankind has learned a lot about the importance of proper lighting practices. Today, when it comes to lighting systems design, engineers and designers take all of these factors into consideration. Manufacturers design fixtures for specific applications to ensure the fixtures perform in a manner consistent with providing the optimal lighting levels for a given application. Wall sconces just aren’t sufficient for roadway lighting, and high bay fixtures would amount to extreme overkill for lighting your bathroom. Electrical Engineers producing lighting designs work with lighting and lighting controls vendors and manufacturers to ensure the proper fixture and controllability is selected for the right application, to ensure the proper how, how much, when and where that meets the needs for the specific application.
Part of this process involves an engineering study commonly referred to as Photometrics, to help assess the expected performance of a selected fixture in a given application. In some cases, Glare, a general sensation produced when the perceivable illumination level is sufficiently greater than what the eyes are adapted to, is a significant concern which may warrant a Glare study to ensure measures are taken in the design to prevent hazards due to glare. These, and others, are important steps towards ensuring the desired lighting performance is achieved to provide a safe, comfortable environment.
But who determines the how much, how, where, and when of lighting design?
It is virtually impossible to finitely define the exact optimal lighting parameters for every conceivable circumstance. Building floorplans, ceiling heights, the reflectance properties of surfaces in the space, roadway configurations, and even the geographical location of project, are all factors that are taken into consideration when producing lighting designs. Sure, there are some applications that can be standardized to a degree, but for the most part there’s just too many variables at play to permit the hard definition of optimal conditions to be rigidly applied to every situation uniformly. Mankind tends to learn from mistakes, and thankfully, as a species it is in our nature to pass on that knowledge to future generations. Lighting design is no exception.
The Illumination Engineering Society (IES) was formed in 1906 and is widely recognized as the “technical and educational authority” on illumination. Essentially, it serves as the go to source for understanding important factors that should be considered in the design for a given application and provides recommendations for appropriate lighting levels for those applications. In addition to the IES, various building codes even identify minimum requirements in specific cases, such as lighting levels for the egress path in buildings, and other circumstances deemed important for public safety.
At the end of the day, the goal is the same. To provide light where it is needed, when it is needed, in a manner that is reliable, safe, and comfortable. Though we can’t quite speak light into existence from nothing, we’ve taken great strides to close that gap as much as humanly possible. And we are doing so in a manner that ensures we can take it for granted, enjoying it’s benefit in a way that is routinely second nature.