Night vision goggles boost a dim, dark scene in a series of simple steps: Dim light from a night scene enters the lens at the front. The light is made of photons (particles of light) of all colors. As the photons enter the goggles, they strike a light-sensitive surface called a photocathode.
Here’s how thermal imaging works:
- A special lens focuses the infrared light emitted by all of the objects in view.
- The focused light is scanned by a phased array of infrared-detector elements. The detector elements create a very detailed temperature pattern called a thermogram. It only takes about one-thirtieth of a second for the detector array to obtain the temperature information to make the thermogram. This information is obtained from several thousand points in the field of view of the detector array.
- The thermogram created by the detector elements is translated into electric impulses.
- The impulses are sent to a signal-processing unit, a circuit board with a dedicated chip that translates the information from the elements into data for the display.
- The signal-processing unit sends the information to the display, where it appears as various colors depending on the intensity of the infrared emission. The combination of all the impulses from all of the elements creates the image.
How do cameras see in the dark?
During the day, when the lighting conditions are right, security cameras work perfectly and are able to capture high resolution images at full color. However, when darkness sets in, surveillance cameras require a source of lighting. … Infrared light is invisible to the human eye, but visible to the cameras.