[LargeFormat] 300mm/f:4.5 Xenar mounting question --> Compound shutter sizes

[Michael Briggs]

On 24-Dec-2003 Ole Tjugen wrote:

> My lens is in a Compound V/12+5FS shutter, which has a diameter of 12cm or
> so. 

Compounds were made in sizes III, IV, and V?   What does "12+5FS" mean?

--Michael