NKS

NKS was the name of a leaf shutter mounted on some Japanese cameras of the 1950s. Various Japanese sources indicate (for example this page by K.Fukushi or this page at Japan Family Camera) that it was made by Nippon Kōsokki Kōgyō K.K. (日本光測機工業株式会社), which also made the Taron cameras.

The usual NKS shutter has B, 1–200 speeds. According to a post by someone who dismantled one, it is a copy of the Prontor II. There is a variant called NKS-FB with B, 1–300 speeds, and another variant called NKS-SC.

On some wartime cameras there is a shutter with T, B, 1–200 speeds marked NKS-TOKIO, it is probably an early variant, and Tokio is probably an alternative writing for Tokyo. An NKS TOKYO marking has also been observed.

Here is an incomplete list of cameras equipped with a NKS shutter (it was not necessarily the only type of shutter available on these models):

• Amiflex
• Atom Six
• Beautyflex
• Daido Six
• Elmoflex
• Gelto (NKS TOKYO marking)
• Gnoflex
• Malcaflex
• Mamiya Six (NKS-TOKIO marking)
• Middl 120-A
• Mihama Six
• Mizuho Six
• Monade Flex
• Ofuna Six
• Pigeon 35 (B-10-200)
• Pigeonflex
• Roico later variant (NKS-TOKIO marking)
• Semi Mihama
• Sunflex
• Toyocaflex
• Zenobia P

Links

In English:

• A post about the NKS shutter at the Classic Camera Repair Forum

In Japanese:

• Tubasaflex Junior and Silverflex at Oozusi's Ricohflex website, the last pictures show an opened NKS B, 10–200.