 Counterillumination has rarely been used for military purposes . " <unk> lighting camouflage " was trialled by Canada 's National Research Council during the Second World War . It involved projecting light on to the sides of ships to match the faint glow of the night sky , requiring awkward external platforms to support the lamps . The Canadian concept was refined in the American Yehudi lights project , and trialled in aircraft including B @-@ 24 Liberators and naval Avengers . The planes were fitted with forward @-@ pointing lamps automatically adjusted to match the brightness of the night sky . This enabled them to approach much closer to a target – within 3 @,@ 000 yards ( 2 @,@ 700 metres ) – before being seen . Counterillumination was made obsolete by radar , and neither diffused lighting camouflage nor Yehudi lights entered active service . 
