A brief history of Nikko Binoculars- and models
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.
The Nikko 20x120 were manufactured in 1942 and came with pillar support. These 45 degree inclined Erfle eyepieces had a 60 degree field with straight through oculars. They were made with a 45 degree Scmidt prism with swivelling rhomboid prism to adjust for IDP (refurbished example).
Nikko also manufactured a 20x120 submarine binocular. This type 97 binoculars would be mounted on the deck outside submarines in a sealed steel case and was produced in 1944. The straight through oculars and Erfle eyepiece rendered a 60 degree field. The objectives would be covered by a 40mm thick glass window and the eyepieces were protected by a steel door. IPD adjustment could be done with a lever between the eyepiece, fastened to gears that rotated the Porro II housings. These binoculars could weigh up to 170 pounds.
The Nikko 25x150 had a Porro II prism and a 60 degree field. The objectives were doublets or Cooke triplets. These binoculars with 250 times magnification and an objective diameter of 150mm were made for naval observation and navigation. They would usually be mounted straight on the deck of the ships of the Japanese navy and now you can find them mounted on heavy duty tripods.
Last but not least, the Nikko 22.5 & 30x180 were manufactured in 1932. These binoculars had a 60 degree field and turret mounted eyepieces. The Porro II prism is joined by Cooke triplets objectives. A pair of these binoculars would easily weigh about 130 pounds.