Thanks for comments .
Yes tripod and gimbal Nod you can't hold that rig still enough even with IS to find it in the first place (well I can't ) and you could not focus holding it and I tend to re focus between burst's of about 5 shots .
The reason I do this is because its moving so fast in the VF you don't have time to look at it and say Yes that's in focus, your panning horizontal and vertical, manual focusing half pressing the shutter and looking at a tiny point of light all at the same time .
by the way I took 300 shots and got around 20 /30 sort of OK ones .
Rob.