Cheers Silky..... for some reason I had just given up , thinking it should easily cope with f/8 at that distance. So I opened up to f/5.6 & was pleasantly surpirsed to get this result from upright Lambency Diffuser :-
& if I opened it up to f/2.8 I managed to be 18 feet away no problems :-
At last
& still being IS0100 I know I have quite a bit more to play with before introducing noise
Goes to show though, how you need to run through tests like this with new kit (eg. Lambency ) to get the best out of it. If I had gone straight to an event with it I would have been lost
Well I'm going to keep playing with different distances & f/stops with this Diffuser until I get a gut feel what it can achieve. Of course it will compeltely change when I get a room with a tall ceiling , but hey