The US Military's "Z Binoculars" c. 1944-45; developed as a compact active IR viewing device that would be used for either night-time driving or in conjunction with weapon mounted illuminators -- during tests with the "Z Binoculars" at Fort Belvoir, VA; they found that if you mounted the active IR light source onto a weapon, all you had to do was move the weapon so that the bright circle of active IR light was illuminating the target's center mass; and fire rapidly -- dispersion would then land most of your shots into the circle of IR illumination.
Edit: 100 of these were ordered c.1945; but with the end of the war after Japan capitulated; the order was canceled.
Edit: 100 of these were ordered c.1945; but with the end of the war after Japan capitulated; the order was canceled.