How does image enhancement work?
Image-enhancement technology is what most people think of when you night vision is mentioned. 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. This technology operates by capturing the upper portion of the infrared light spectrum, which is emitted as heat by objects instead of simply reflected as light. Hotter objects, such as warm bodies, emit more of this light than cooler objects like trees or buildings. The image-intensifier tube changes photons to electrons and back again. Here’s how image enhancement works: A conventional lens, called the objective lens, captures ambient light and some near-infrared light. The gathered light is sent to the image-intensifier tube. 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 ligh
