Thanks for the indepth discussion guys. . .. I didn't realise it was such a difficult question to answer:-)

I think I will just leave auto shutter on in the menu, move the slider to the middle and select the shutter, gain and iris to make sure I am in full manual mode when required.

One thing that seems fairly obvious to me is that the Sony manual could have detailed the subject and options a lot better than the simple overview that is in there now.

Regards,
Mark Sudfelt