Kamakura do supply for Leupold as well as well as Vixen, Nikon, Pentax, and Minox. They also assemble binos in the Phillipines - where production is cheaper - which is where my Leupold Acadias come from. The Olympics, Pinnacles, Cascades are directly Japanese sourced.

There is another Japanese binocular maker called 'Light optical works' [site below]. They supply for Bushnell - however it is difficult to find out who else they supply for. They also assemble some binos. in the Phillipines as does Nikon - again cheaper labour.

There was another Japanese maunfacture called 'Hakko' but I cannot find much info on them.

A usually getting info on Japanese OEM manufactures is difficult and is kept somewhat secretive.

I think we would be surprised that how many 'name' binos come from the same factory that use Japanese supplied lens and - the only differences between 'high end' and 'low end' binos comes down to quality control - and how much the importer is willing to pay for this.

http://www.light-op.co.jp/LIGHT_ENGLISH/index.html