How Night Vision Works

Detective work is greatly limited by the darkness that comes with nightfall, but this challenge is overcome when night vision devices are utilized. Those who have never used such devices might question their effectiveness. This doubt is quickly erased once it is understood how night vision works.

Image enhancement makes a brighter place

Two different technologies are employed in devices that accomplish similar night vision goals. The first, image enhancement, is the more common technology. A conventional lens gathers ambient and infrared light. This light is then passed through a tube, called a photocathode, that multiplies the light to thousands of times it normal brightness. The image is displayed on a screen coated in phosphors, which allows the light particles to remain in constant alignment.

The heat is on thermal imaging devices

The second night vision technology comes through the use of thermal imaging. Anything that consumes energy must generate heat, and heat produces light in the thermal-infrared spectrum. Thermal night vision devices gather this otherwise invisible light through special focusing lenses. The temperature variations are read by using a thermogram, and the details of this reading is interpreted by a computer chip. Once interpreted, the data is translated into a graphic form that is transmitted to a display.

These technologies greatly enhance the options available to those seeking to perform detective work in dark settings. Image enhancement devices are generally cheaper and more durable. Thermal imaging devices cost a bit more, but allow users to see in darker conditions. Any of these amazing devices can serve a detective well, and the best method of selecting one is through research and experimentation.