Generation I technology is obsolete in the US market. In November 1999, Litton introduced the new Generation IV Unfilmed image intensifier technology, which significantly enhances the operational envelope in the darkest flight regimes as well as in high ambient light urban environments. Litton's new image intensifier tubes equipped with an auto-gated TM power supply allow helicopter and fixed wing pilots immediate and seamless transition while scanning across varied illumination backgrounds. More information in Generation IV technology will be discussed as the information becomes available. Litton always uses new tubes so reliability is guaranteed.
Most natural backgrounds reflect infrared light more readily than visible light.
When reflectance differences between discernable objects are maximized, viewing contrast increases, making potential terrain hazards and targets far more distinguishable. Gen III's high infrared response complements this phenomenon, creating a sharper, more informative image. The early 1960's was witness to the beginning of passive night vision. I devices lacked the sensitivity and light amplification necessary to see below full moonlight, and were often staged or cascaded to improve gain. They were also characterized by streaking and distortion.