On the 25th of July, 1917, three leading optical manufacturers (Fuji, Tokyo Keiki Seisaku Sho and Iwaki Glass) joined together to form Nippon Kogaku K. K. Though we know the company now as Nikon Corporation, famous for its professional photo equipment of the same name, the company actually started as a fully integrated optical company. When forming the company, their goal was to manufacture optical munitions, more specifically binoculars for the Japanese armed forces.
The reason behind starting their own company was simple: the Japanese binocular industry started with optical glass from Germany but that became scarce due to World War I. That is why the Japanese government encouraged its companies to start making their own. That is what Nippon Kogaku K. K. was created for: to design and produce optical lenses in Japan. After the war had ended, they also started producing photographic lenses, which became the standard for Naval Binoculars used in the second World War. In fact, Nippon Kogaku became the biggest producer of large military binoculars during WWII and their designs were copied by the American and British forces. Below, we will be looking at some of these Big Eye binoculars used by the Japanese armed forces during World War II.
The Nikko 15x80 degrees was manufactured in 1943 with naval optics. These huge binoculars measured 18 inches long and 8,5 inches wide and weighed approximately 25 pounds. These binoculars with straight through oculars had Erfle eyepieces and a 60 degree field. It boasted a Porro II prism and the objectives were airspaced achromats.
The Nikko 15x100 with 15 power magnification and 100mm objective lenses were large scale military binoculars with straight through oculars. They had a 60 degree apparent field and a three element Cooke type lens for objective, allowing for shorter focal length.