Without the proper lighting, you may be buying a load of trouble. The man on the left is pointing a cell phone. The one on the right is pointing a pistol.
Contrast and Movement
The above diagram shows the dramatic reduction in the amount of subject illumination as the distance from the source increases. We need to understand how contrast and movement impact our ability to identify objects and actions and our decision-making process.
Mistake-of-fact shootings happen in all environments and traffic stops are no exception. In one of the above photos the subject is standing 40 feet from the light source and pointing a cell phone. In the other photo, he is pointing a Glock 23. Given a split-second to make a determination it is easy to see how the subject’s movements will have a huge impact on our ultimate interpretation of what we observe.
I often refer to this as "visual patience." We must work at developing our visual patience whenever we are deploying light. The mind's eye wants to fill in the blanks, and when our eyes can't see some specific detail, the mind wants to complete the picture, which can easily mislead us to a mistake-of-fact shooting.
An example of contrast is represented in the photo above. In an effort for clarity, I chose the extremes in contrast white and black. You can imagine how correct interpretations become more difficult when looking at the contrast between brown and tan or gray and silver, just to mention a few. The subject in these pictures is standing 40 feet from the light source with a Glock tucked into his pants.
Light and Vision
There are no routine traffic stops. We all understand that anything can happen at any time. When we add darkness to this equation even the simple becomes more complex. If we understand how our bodies and minds react to the absence of light we can adjust our tactics to our advantage.
Our eyes react differently to various light conditions. There are three types of vision that relate directly to ambient light conditions: photopic, mesopic, and scotopic.
Exposed to higher levels of light, we use primarily the cones of the eyes. This is called photopic vision. Photopic vision is categorized by our ability to determine color and detail and a lack of light sensitivity. In low-light situations we rely primarily on our rods, and this is called scotopic vision. Scotopic vision limits our ability to determine color, but we tend to pick up movement and of course our eyes are very sensitive to bright light. The last and more complex condition is mesopic vision, which uses the bottoms of the cones and the tops of the rods. Mesopic vision typically is encountered when we are exposed to street lights, parking lot lights, and traffic headlights. During mesopic vision, we are in between full reliance on rods or cones and therefore what we can see depends on which is most dominant based on the true light level.
It is clear to most of us that we adapt to light much faster than to darkness. When we transition to a darkened environment it takes about 30 minutes to transition completely from the cones to the rods. In contrast we can complete the transition from dark to light in less than two minutes.
Using light to control your subject during a nighttime traffic stop is very important. How often have you heard, "Watch the hands; it's the hands that are going to hurt you?" I recommend that when necessary you keep the light hotspot in the eyes of your subject. You will have enough light to see the hands, but you will be in control of the subject. Not only will the subject be disoriented, but he or she will not be able to assess you, look for weapons of opportunity, and perform other tasks necessary to attack you.
Take the time to learn how to use your equipment to your advantage. Develop consistencies in how you do your job. Do not let traffic stops become a routine, especially at night.
Edward M. Santos is the owner and founder of Center Target Sports and an expert in low-light tactics.