How Night Vision Works Image Enhancement
Image-enhancement technology is what most people think of when you talk about night vision. In fact, image-enhancement systems are normally called night-vision devices (NVDs). NVDs rely on a special tube, called an image-intensifier tube , to collect and amplify infrared and visible light. Here's how image enhancement works: A conventional lens, called the , captures ambient light and some near-infrared light. The gathered light is sent to the image-intensifier tube. In most NVDs, the power supply for the image-intensifier tube receives power from two N-Cell or two "AA" batteries. The tube outputs a high voltage, about 5,000 volts, to the image-tube components. The image-intensifier tube has a photocathode , which is used to convert the photons of light energy into electrons. As the electrons pass through the tube, similar electrons are released f...