Although Modern binoculars have brighter and sometimes better image, there are many interesting mechanical and optical features to be found in old binoculars. One can see the reflection of enthusiasm and efforts made, by authentic workmanship, in the innovative binocular design and in unique mechanisms.
Beginning of production of prismatic binoculars in Japan.
The first prismatic binoculars produced in Japan were designed after studying prismatic binoculars made by Ross(Britain).
To manufacture binoculars in that period in Japan, polishing machines and measuring instruments, optical glass materials were imported from Germany in those days. One of the binocular's feature is to have fixed the prisms on the back side of the upper and lower prism covers to wipe prisms easily when optics become hazy or mould grow. However for me, cleaning of the prism was difficult because prisms were fixed by bending edges of metal housing. Effective diameter of the objective lens is 20mm and the apparent field of view is about 40 degrees. The manufacturer's serial number is not engraved. Prism covers are made of aluminum alloy. I wonder what year these binoculars were marketed in Japan and how many numbers were produced.It is marvellous that Ryuzo and Kozo Fujii produced the first Japanese prismatic binoculars only about 15 years after Zeiss produced their first one. Meiji Restoration was in 1867 and the Fujii lens factory was established by Ryuzo and Kozo to make the optical instruments domestically in 1909.
Reference: "Kohgaku Kaikoroku (meaning: Memories of Optics)"written by Ryuzo Fujii
(Description;Victor the first binoculars produced in Japan )
Soon Fujii bros. adopted the Zeiss style in their binoculars. Construction of these binoculars resembles the Zeiss model(D.F.6x21) at that time. Effective diameter of objective lens is 22mm and apparent field of view is about 45 degrees. These are export model since letters "MADE IN JAPAN" are engraved.
I have a similar pair of binoculars for domestic on which "VICTOR No4" is engraved. In Fujii's 1912 catalogue , it is written that they were recommended by Japanese army and navy to change name of their binoculars from English name "Victor" to Japanese name.
Effective diameter of objective lens is 30mm and apparent field of view is about 50 degrees.
It is written in "Kohgaku Kaikoroku" that Ryuzo Fujii stayed in Britain and purchased a pair of binoculars made by Ross in around 1897. That was one of the first Ross prismatic model.
I think the binoculars were quite similar because the construction of prism covers are identical to fujii's 8x20 although their size is larger.
