Difference between revisions of "Night Vision"

Revision as of 00:14, 1 January 2025

1. Active Illumination
2. Image Intensification
3. Thermal Imaging

Active Illumination

Lowest cost. This is basically an infrared camera working with an infrared illuminator. Range is limited to distance of infrared source. Easily detectable. The light source is closer to the visual portion of the spectrum so that it is near visible yet still below human eye perception.

These work well for CCTV cameras, video cameras, and indoor night vision requirements. This is typically a digital technology.

Image Intensification

Vietnam War era "Starlight Scope" and modern Military NVGS fall into this category. Uses only existing light and through magnification the light level is useful to the human eye. These are lighter and more real time. They produce no detectable light source. Typically there is a limited field of view with no peripheral view. Multiple lens versions that are military grade can retail for up to $40,000 such as those used by Navy S.E.A.L. teams. This is an analog technology using electrical image intensifiers. These will not produce any image if there is no available light, such as in a completely dark room sealed from any light entering.

Resolution is measured by "line pairs to millimeter". Military grade NVGS are required to be a minimum of 64 line pairs per millimeter.

Thermal Imaging

Requires no external light source so it can be useful when outdoors or in a completely dark room without any light. Operates by detecting long-wave infrared light which is an emissive light source. Thermal Imaging works well in fog and smoke unlike the other two night vision types.