Luna
The S. Luna is a shutter mounted on several Japanese cameras of the 1950s. The "S" in the name probably stands for "flash-synchronized". The speeds are B, 1–200 and there is a self-timer. The shutter was announced as a "T.S.K. Luna" in the user manual of the Cosmoflex II, certainly indicating that it was made by Tōyō Seiki Kōgaku and related to the TSK shutter.
Extract of the user manual of the Cosmoflex II. (Image rights)
Cameras fitted with an S. Luna
Listing of a camera here does not imply that all examples were fitted with (S.) Luna shutters; merely that some examples were.
