Hi All, I have just bought a Sinar Copal shutter cable that cocks the shutter when a dds is inserted in the back. However the hole on the bottom of the back is threaded and the end of the cable has two ears on it looking like it fits into some kind of bayonet arrangment Obviously the two items are not compatable....The question is why? My back is on a Sinar 'C' so it is the wrong back or are the cables for a Norma back (the shutter end is fine)

Any advice much appreciated......Cheers Dave