Also the other thing is I was just playing around with a single speedlight with my Nikon D600 on a white/black brolly. I found that it was consistantly underexposing - is that right? I tended to use +1.3 or +2.0. This was night time indoors with lights off or around 4pm with overcast day. The camera settings were set to the max flash-x speed 1/200 on this and F5.6 which without the flash would been severely underexposing. Are the TTL flash not able to work intelligently in these situations - are they only for mid tone day time type of scenes?
Has anyone used the Profoto B1's and how is the TTL like on them?